GMOs: Facts About Genetically Modified Food

Introduction

I am giving a review on an article from Marc Lallanilla ( January 11, 2016 ) titled Facts About Genetically Modified Food. I am going to discuss the issues that are currently happening in Genetically Modified Organism such as how safe they are, the labelling issue and the politics of Genetically Modified Organism . Later on, I did some study on misconceptions that people often did on Genetically Modified Organism. It is important for people out there to acknowledge on this so that they know what are they eating and so that they are staying on eating on a right track.

Body

1) What is GMO ?

A genetically modified organism, or GMO, is an organism that has had its DNA altered or modified in some way through genetic engineering.In most cases, GMOs have been altered with DNA from another organism, be it a bacterium, plant, virus or animal; these organisms are sometimes referred to as "transgenic" organisms. A genefrom a spider that helps the arachnid produce silk, for example, could be inserted into the DNA of an ordinary goat.

2) How safe are GMOs?

From the article, it is said that there are two very different viewpoints when it comes to the health and safety of genetically engineered food .Vocal anti-GMO activists who refer to GMO crops as "Frankenfoods" argued that GMOs can cause environmental damage and health problems for consumers.Mary Vandewiele, co-owner of The Better Health Store, a chain of 14 health-oriented stores, says that the long-term effect of GMOs remain unknown. “In reading the literature, most of the science and myths are not clear and appear to be intertwined. GMOs have clearly impacted our food industry but to what extent the damage is and can be long term, appears to be uncertain and that is a problem.”However, many scientific organizations believe the fear-mongering that runs through discussions of GMO foods is more emotional than factual. 

Others point goes to the benefits of sturdier crops with higher yields. "GM crops can improve yields for farmers, reduce draws on natural resources and fossil fuels and provide nutritional benefits," according to a statement on the website for Monsanto, the world's largest manufacturer of GMOs. 

From my point of view, the GMO supporter does not give their proof on how safe to eat the GMO foods. In fact, they are discussing of how GMOs going to benefit the farmers of industrial agriculture by producing higher number of crops yielded.

3) GMO labeling debated

In November 2015, the FDA issued a ruling that only requires additional labeling of foods derived from genetically engineered sources if there is a material difference — such as a different nutritional profile — between the GMO product and its non-GMO equivalent. 

“[In addition to the FDA ruling], recently the American Medical Association re-affirmed that there is no scientific justification for special labeling of foods that contain GM ingredients; the American Association for the Advancement of Science stated a similar stance. We support these positions and the FDA’s approach,” according to Monsanto. “Additionally, many independent scientists and organizations around the world — such as the U.S. National Academy of Sciences, United Nations Food and Agriculture Organization, World Health Organization, American Medical Association and the American Association for Advancement of Science have looked at thousands of scientific studies and concluded that GM food crops do not pose more risks to people, animals or the environment than any other foods.”

The argument over the development and marketing of GMO foods clearly was a hot issue by these recent years.

4) The politics of GMOs

In addition to the scientific debate over GMOs, genetically modified foods have also become a political football. Rep. Mike Pompeo (R-Kan.) sponsored a bill that would block state and local laws from requiring food labels to disclose genetically engineered ingredients, according to the Washington Post. Meanwhile, Vermont, Connecticut and Maine have passed mandatory labeling laws for genetically modified food. At least 15 other states are considering similar regulations.”

In 2012, voters in California were asked if food made from GMOs should be labeled as such. The initiative was defeated — but only after GMO proponents like Monsanto, General Mills, Pepsico, DuPont, Hershey, Cargill, Kellogg, Hormel, Kraft, Mars, Goya, Ocean Spray, Nestle and other industrial food marketers spent millions on advertising to convince voters to vote against the measure.

Opponents in several states and countries continue to push for GMO labels on foods if not outright bans on GMO foods but industry and science insists the foods are safe, labels aren't needed and they'll just confuse consumers.

Discussion/Conclusion

It seems that there are many questionable issues about GMOs. From what I see, the never ending debates are mostly caused by the misconceptions that many people do not know and from that, some of them insisted of wanting the labels to be put. The misconceptions include :

 The new labels will make it uniformly easy to identify what has been genetically engineered.

Actually: Consumers may need to scan a package to see if an ingredient was genetically modified, and even then they are unlikely to learn which traits were altered or why. At the most basic level, a G.M.O. is a plant or animal whose DNA was altered in a laboratory, often by inserting genes from a distant species into its cells with the help of a bacterium or with other tools. Many major food manufacturers are loath to put the words “genetic engineering” on labels for fear that they will convey an impression that the foods are suspect. Under the new law, manufacturers can instead label packages with a symbol denoting genetically engineered ingredients, or a “quick response” (Q.R.) code that people with smartphones could scan to retrieve the information.

Apart from that, most of the industries are more likely to put aside those labelling matter because it might burden their work as well as having to consider about the costs that it will take to change from what it used to be. The industry and science insists the foods are safe, labels aren't needed and they'll just confuse consumers. 

For me, I support the labelling of GMOs on product. If the science said that it does not matter because it will just confuse the customers, hence the government should spread the truth behind GMO products such as what are their benefits or what are their effects on certain people who have allergies and stuff like that. What’s important is just put the label so that sooner or later, people will have acknowledge more on what they eat instead of eating blindly.  

Abstract

I am doing a personal review on an article titled Facts About Genetically Modified Food. There are some issues happening and it had taken more on the labelling issue. There are a few readings that I made from different resources to clear up a misconception that people probably experience based on this issue that might lead to the labelling issue. I am also giving my opinion whether to support the labelling or not. 

References

1) https://www.livescience.com/40895-gmo-facts.html

2) https://www.fda.gov/aboutfda/transparency/basics/ucm194877.htm

3) https://www.nytimes.com/interactive/2016/07/12/science/gmo-misconceptions.html

4) science.howstuffworks.com › Science › Life Science › Genetic Science

Article Review : Your Cell Phone Is 10 Times Dirtier Than a Toilet Seat. Here's What to Do About It

• Introduction

This time, I am going to review an article research from the time.com by Abigail Abrams (Aug 23, 2017). The title of this article is “Your Cell Phone Is 10 Times Dirtier Than a Toilet Seat. Here's What to Do About It.” By the title, we can somehow know what will be it discussing about. The idea of it is about how dirty and harmful the bacterias are and what are the steps to prevent the bacterias from living on something that we very often used in our daily lives which is our phones. Eventhough it just look like something trivial to be discussed, it never crossed most of our minds that this can be very important to know since I am very sure that all of us owned at least 1 phone for whatever the reasons are. It is important to know this because we all living in a community that interacts each other by phones and since the phones may contain harmful bacterias, I am sure that we all want to eliminate those bacterias and life in the healthiest state of our lives.

• Body

This article said that most people do not give a second thought to using their cell phone everywhere, from their morning commute to the dinner table to the doctor’s office and research shows that cell phones are far dirtier than most people think, and the more germs they collect, the more germs we touch. According to a survey by Deloitte, Americans check their phones about 47 times per day, which contributes to plenty of opportunities for microorganisms to move from our fingers to our phones. I agree with what the writer had said because people are always carrying their cell phones even in situations where they would normally wash their hands before doing anything, hence the  cell phones do tend to get pretty gross.  

In the article, they made some studies and it is found that there are presences of serious pathogens on cell phones, including Streptococcus, MRSA and even E. coli. To clarify things better, I have made a research to explain about these type of pathogens. Streptococcus species are responsible for many cases of pink eye, meningitis, bacterial pneumonia, endocarditis, erysipelas, and necrotizing fasciitis (the 'flesh-eating' bacterial infections). However, many streptococcal species are not pathogenic, and form part of the commensal human microbiota of the mouth, skin, intestine, and upper respiratory tract.

While MRSA stands for Methicillin-resistant Staphylococcus aureus, it is an infection caused by a type of Staphylococcus, or staph, bacteria that is resistant to many different antibiotics. These bacteria naturally live in the nose and on the skin and generally do not cause any harm. However, when they begin to multiply uncontrollably, a MRSA infection can occur. These infections typically occur when there is a cut or break in our skin. MRSA is very contagious and can be spread through direct contact with an infected person. It can also be contracted by coming into contact with an object or surface that an infected person has touched. Though a MRSA infection can be serious, it may be treated effectively with certain  antibiotics.

Meanwhile, E. coli is a type of bacteria that normally live in the intestines of people and animals. Symptoms of intestinal infection include diarrhea, abdominal pain, and fever. More severe cases can lead to bloody diarrhea, dehydration, or even kidney failure.People with weakened immune systems, pregnant women, young children, and older adults are at increased risk for developing these complications. Most intestinal infections are caused by contaminated food or water. Proper food preparation and good hygiene can greatly decrease your chances of developing an intestinal infection.Most cases of intestinal E. coli infection can be treated at home. Symptoms generally resolve within a few days to a week.

Then the writer said again that just having these microbes on our phone will not automatically make us sick, but we still do not want to let them enter our system. She then strengthen her opinion by restating of what the Emily Martin, assistant professor of epidemiology at the University of Michigan School of Public Health said which is “research has varied on just how many germs are crawling on the average cell phone, but a recent study found more than 17,000 bacterial gene copies on the phones of high school students. Scientists at the University of Arizona have found that cell phones carry 10 times more bacteria than most toilet seats.”

Now, since she confidently said that cell phones carry 10 times more bacteria than most toilet seats, I made some research on what are the “Top types of bacterias that can be found of phones and toilet seats” and compared them two. 

Top types of the most dangerous bacterias which can be found on our phones :

1) Coliforms

Coliforms are organisms often found in animal and human feces, as well as on soil and plants

2) Escherichia Coli

E. coli O157:H7 is the one to blame for those foodborne outbreaks that we see in movies and local news broadcasts.

3) Staphylococcus Aureus

For decades, scientists have developed new medicines to stay ahead of the ever-mutating enemy, bacteria. But now Methicillin-resistant Staphylococcus aureus (MRSA) kills more people in the U.S. than AIDS-related complications.

4) Streptococcus

It can cause more serious maladies, like scarlet fever, toxic shock syndrome, cellulitis (infection that causes the skin to swell) and a flesh-eating disease called necrotizing fasciitis.

5) Coagulase Negative Staphylococci (CoNS)

Coagulase Negative Staphylococci is responsible for 30 percent of health care-related blood infections.

6) Molds

Exposure to mold is likely to affect the respiratory system, resulting in shortness of breath, nasal stuffiness, fever and—in less common cases—lung infection.

7) Yeasts

Yeast infections cause immense itching on your skin or vagina and in the case of the vagina, a discharge as well.

8) Clostridium Difficile

C. difficile is known to cause other conditions, like fever, nausea, abdominal pain and loss of appetite.

9) Corynebacterium

It's a pathogen whose toxic strains cause diphtheria, a potentially deadly disease in which toxins coat the infected person's throat and make it difficult to breathe.

10) Pseudomonas Aeruginosa

It has this amazing ability to resist treatment after infection.

Top types of the most dangerous bacterias which can be found on the toilet seats  :

1) Escherichia Coli

E. coli O157:H7 is the one to blame for those foodborne outbreaks that we see in movies and local news broadcasts.

2) Shigella Bacteria

Shigellosis causes infectious, severe diarrhea, abdominal cramping and other gastrointestinal distress that may last for about a week

3) Streptococcus

It can cause more serious maladies, like scarlet fever, toxic shock syndrome, cellulitis (infection that causes the skin to swell) and a flesh-eating disease called necrotizing fasciitis.

4) Staphylococcus

Methicillin-resistant Staphylococcus aureus (MRSA), for example, can live on a toilet seat -- and any nonporous part of a toilet -- for more than two months.

5) Influenza (and the Common Cold)

It can also live on almost any other surface you touch. It's easily transmitted through mucous membranes.

Finally, the writes suggests that keeping our phone out of the bathroom will help, but if we want to clean our phone, a few different methods will work. Many people just wipe their phones with a soft microfiber cloth, which will remove many of the germs. For a deeper clean, Whittier recommends using a combination of 60% water and 40% rubbing alcohol. Mix the ingredients together, and then dip a cloth in the solution before wiping it gently across our phone. Stay away from liquid or spray cleaners, which can damage your phone .Still, the best advice has more to do with you than the phone. Wash our hands several times a day, the experts say, and we will likely be just fine.

• Discussion/Conclusion

In a nutshell, I have dig deeper to answer the question which is, is it really true that “Your Cell Phone Is 10 Times Dirtier Than a Toilet Seat? ”. By the research and comparisons that I made early, I am kind of agree to what the writer has said in only in certain condition and I am not agree for what she said in certain condition. I am not agreeing to that is because I am not 100 percently sure that the calculation would be solidly 10 times dirtier. It could be 9 times, 7 times or even just 2 times dirtier but basically I do believe that the phones are dirtier than toilet seats if only the phones has never been sanitized or taken care of hygienely by the owner. From the top bacteria that I found by some researches, 10 bacterias are at the top for phones and only 5 bacterias are at the top for toilet seats. Surely these bacterias are not applied to all the phones and the toilet seats in this world because it is only from the average research that the professionals have made in America. Also, we need to consider how often ones touched a phone, what kind of job do they work and things like that. It is unfair to say that everyone’s phone is dirtier. But what makes me agree that the phones might be dirtier than the toilet seats is because, logically, people bring their phones almost to everywhere. Even in the toilet room. When toilets flush, they spread germs everywhere, which is how phones end up with fecal bacteria like E. coli. Then, we might go to the store and pay using cash to the counter. After that, without washing our hands we touched our phones. Look, we have just collected variety types of bacteria starting from the microorganisms in the toilet, on the cash, on the groceries, the steering of the car, all ended up at a phone and these are from a few places. What if we count all the places that the bacterias might sit through our journey all the day. It must be way a lot. So as a teacher to be, I want to spread to all the students or people out there on the awareness of how important it is to clean and sanitize our phones. Living in the millennium world these days with so much discoverings of new unbelievably diseases, it is a responsibility for ones to spread informations they know to all because one simple trivial looking awareness might change the filthy lifestory of a people to a new healthier one. 

• Abstract

I am doing a personal review on an article titled “Your Cell Phone Is 10 Times Dirtier Than a Toilet Seat. Here's What to Do About It.” I am questioning and stressing more on “how can the cell phones get 10 times dirtier than the toilet seats” rather than the solution which is “ on how to do about it”. There are a few researches that I made from different resources and later on I did the comparison and logical thinking to prove that my opinion is strong. Reading this surely can change someone’s life. One simple step can change the whole story. Enjoy.

• References

http://time.com/4908654/cell-phone-bacteria

http://science.howstuffworks.com/life/cellular-microscopic/top-10-germs-smartphone.htm

http://health.howstuffworks.com/diseases-conditions/infectious/5-diseases-toilet.htm

Online Resources

Here is the link of another online resources that you all can refer. Enjoy your reading !

https://norlinsuhaiza95.wixsite.com/mysite

Biodata

BIODATA

Personal

Name                          : Norlin Suhaiza Bt Musali

Gender                        : Female

Date of Birth                : 30 August 1995

Race                           : Malay

Religion                       : Islam

Nationality                   : Malaysian

Origin                          : Pahang

Interest                        : Cats

Hobbies                       : Listen to songs

Family

Father’s Name            : Musali Bin Zulkaranain

Occupation                 : Businessman

Mother’s Name           : Noraishah Binti Mat Arof

Occupation                 : Retired

Siblings                        : 3

Position in Family        : 3^rd daughter

Education

Primary School           : SK Sungai Gau

Secondary School      : SMA Al-Khairiah

University                    : Sultan Idris Education University

CAREER DEVELOPMENT PLAN

My name is Norlin Suhaiza Bt Musali and I am currently doing my degree in Chemistry Education at Sultan Idris Education University. Now I am at the third semester and there are 5 semesters left before I could finished my degree. Through all the hardships that I went, I wished I can be an excellent educator. Though I am now doing my degree and it will lead me to be as a teacher, I have the intention of being a lecturer.

Since I am now taking a major in Chemistry and minor in Biology, I did not mind to continue my next level studies whether in Chemistry or Biology as I love both of them. I planned to give the best grade as possible so that I can get a scholarship during the time I pursue my studies in Master level. After finishing Master level, I wish I will be strong enough to pursue my studies in Phd level. Having a Dr. title in front of my name was my dream since I was a kid. To achieve all of these, I need to improve myself by gaining the skill of effective study so I can be excellent in each of the semester. Improving my study style includes the high self determination to keep on studying without wasting too much time and prohibiting the biggest study disease which is procrastination. Plus, since I always fill my semester breaks being a tuition teacher, I hope it somehow adds my self-enrichment as a preparation to go teaching to the school after posting. With all these plans, I hope my career plan will become as real as I hope it will be and I hope it went smoothly.

MY TEACHING PHILOSOPHY

Being a teacher does not sound as easy as it heard. People often sees a teacher as an incomparable high-credibility person. This is because, a teacher’s role is to educate people. For me, the effectiveness of a teacher’s teaching determines the level of people’s perspective towards them. We should use the best method of sending the knowledge to the students so that they can understand easier. It is a holistic teaching method designed to integrate critical thought, examination of emotion and moral values and factual data to broaden the learning experience and make it more relevant to everyday life situations. A successful teacher has his/her own way of conducting situations. They have clear objectives. In the world of education, our objectives for the students act as road signs to our destination. The plan is the map. Making a plan does not suggest a lack of creativity in the curriculum but rather, gives creativity a framework in which to flourish. Besides that, successful teachers enjoy their work. It means that they do not feel burdened by the tasks. With the advance of technology, there are fresh new resources and tools that can add great functionality to the classroom and curriculum. Teachers can give the students a headstart and use technology in the classroom to add the creativeness so that they will not feel so bored and lame. Also, successful teachers are masters of their subject. Good teachers need to expert themselves where to head to. We need to master our subject area so that we can spread the knowledge without any doubt.

Assignments

Presentation

https://drive.google.com/file/d/0B46gdNP7n0K2d25yUzUzUlBhZ1E/view?usp=sharing

Crossword Puzzle

https://drive.google.com/file/d/0B46gdNP7n0K2enNDUlVtQmZnSjQ/view?usp=sharing

Wordsearch

https://drive.google.com/file/d/0B46gdNP7n0K2ZTVpLXBmMkFvX1U/view?usp=sharing

Simulation

https://drive.google.com/file/d/0B46gdNP7n0K2ck1DS0ZDNE9ZNXM/view?usp=sharing

Moviemaker

https://drive.google.com/file/d/0B46gdNP7n0K2LW9FUWRGbVdJNXM/view?usp=sharing

Prezi

https://prezi.com/l0dkwo2i2xry/structure-of-an-atom/

Reflections on hands-on activities and class sessions

This SKI 3013 class really teaches me a lot especially on doing works by using the application of the technology. Before attending this class, I did many things on just by Microsoft Word, Microsoft Excel, Movie Maker and Microsoft Powerpoint without knowing that there are a lot more of perisian that I can up to. Since every class session teaches me on how to use perisian differently, I learnt new things every week and by that, I applied it to my assignment on different subjects. It surely made my job easier.

The hands-on activities, also somehow helps me to implement what I learnt into every tasks given. The activities given are suitable for us to improve our learning session. By doing all these activities constantly, I can practice a lot more on my own. It is good to give a lot of hands-on activities since practice makes it all perfect. What makes this subject important is that when we are out as teachers, we can vary the way of teaching to the students so that they would not be bored by the same pattern and style like the normal teacher would do. When students becoming more interested, it automatically reset their minds that the Chemistry subject is not as hard as they thought. In fact, it can be easily understood by the new learning way that is way cooler than before. In a nutshell, it is very important for the teachers to learn and expert the new perisian so that their teaching sessions will be more effective and fun.

Structure of Atom

1) History Of Development Of The Model Of Atom

Table below shows the scientists that contribute to the development of the Model of Atom.

John Dalton	Five main points of Dalton's Atomic Theory All matter is composed of extremely small particles called atoms. All atoms of a given element are identical, having the same size, mass, and chemical properties. Atoms of a specific element are different from those of any other element. Atoms cannot be created, divided into smaller particles, or destroyed. Different atoms combine in simple whole-number ratios to form compounds. In a chemical reaction, atoms are separated, combined, or rearranged. Weakness Atoms consist of even smaller particles called electrons, protons and neutrons. Atoms can be created and destroyed in the nuclear reactions such as nuclear fusion and nuclear fission.. Atoms of the same element can have different physical properties, for example, isotopes of hydrogen.
J.J. Thomson	The electrons were positioned uniformly throughout the atom.
Ernest Rutherford	the atom is mostly empty space, most of the atom's mass concentrated in a tiny center, the nucleus and electrons being held in orbit around it by electrostatic attraction. The nucleus was around 10-15 meters in diameter, in the centre of a 10-10 metre diameter atom. Those alpha particles that had come into close proximity with the nucleus had been strongly deflected whereas the majority had passed at a relatively great distance to it.
Neils Bohr	Electrons in an atom of an element are not randomly distributed around the atomic nucleus. Electrons move around the nucleus in fixed orbits. Each orbit forms a circle and has a fixed distance from the nucleus.
James Chadwick	Chadwick discovered the presence of neutrons in the nucleus. He concluded that the nucleus contains another tiny particle known as a neutron that has no charge. The neutron mass is almost similar to the proton mass. All nuclei contain protons and neutrons, except for the hydrogen which contains protons. only

2) Modern Atomic Model

According to the modern atomic model,

1. The central nucleus consists of protons and neutrons. It containing almost all the mass of the atom.
2. the nucleus of an atom is very small compared to the size of the atom
3. the electrons are orbiting outside the nucleus in the electron shells
4. the electrons are moving in electron shells at a very high speed and we cannot determine the position of the electrons at a particular time

3) The Subatomic Particles Of An Atom

1. Atoms are made up of tiny particles called subatomic particles.
2. An atom contains three types of subatomic particles: 
1. proton, 
2. neutron and 
3. electron, 
3. The proton and neutron form the nucleus at the centre of an atom. They are also called the nucleon of an atom.
4. The electron moves around the nucleus at a very high speed.
5. The nucleus is positively charged because of the presence of protons, which are positively charged. The neutrons are neutral.
6. The symbols, charge and relative masses of proton, neutron and electron are as below.

Particle	Symbol	Relative charge	Relative mass
Proton	p	+1	1
Neutron	n	0	1
Electron	e	-1	1/1840

4) The Charge Of Particles

1. A neutral atom contains the same number of electrons as the protons. 
2. The positive and negative charges of the protons and electrons respectively neutralise each other, for example, (+4) + (-4) = 0
3. If the number of protons is greater than the number of electron, the particle is positively charge.
4. If the number of protons is greater than the number of electron, the particle is positively charge.

Example:

Number of proton	Number of electron	Charge
3	3	0
5	2	+3
9	10	-1
11	10	+3
16	18	-2
17	18	-1
20	18	+3

5) Proton Number And Nucleon Number

1. Proton number = the number of protons
2. Nucleon number = Number of protons + Number of neutrons

Proton Number

1. The proton number (Z) represent the number of protons found in the nucleus of an atom. 
2. Proton number = the number of protons
3. The proton number is also known as the atomic number.
4. In an atom of neutral charge, the number of electrons also equals the atomic number.
5. Hence, the proton number of an atom can also represent the number of electrons.

Nucleon Number

1. The nucleon number (A), also called atomic mass number or mass number, is the number of protons plus the number of neutrons in an atomic nucleus. (Nucleon number = Number of protons + Number of neutrons)
2. The nucleon number of an atom is about the same as the mass of the atom because the mass of an electron is very small and can be ignored.

Atom	Proton Number	Nucleon Number	Amount of Proton	Amount of electron	Amount of Neutron
Helium	2	4	2	2	2
Oxygen	8	16	8	8	8
Sodium	11	23	11	11	12
Chlorine	17	35	17	17	18

[Notes: In ion, the amount of protons IS NOT equal to the amount of electrons]

6)  Isotopes

Isotopes are atoms of certain elements which have the same number of protons but different number of neutrons in the nucleus of the atoms.

It can also be defined as atoms of certain elements with the same proton numbers but with different nucleon numbers.

Properties of Isotope
Number of proton	equal
Number of neutron	difference
Chemical properties	same
Physical properties	difference

Example:

Element	Name	Symbol	Proton Number	Nucleon Number	Number of proton	Number of neutron
Hydrogen	Hydrogen	11H	1	1	1	0
	Deuterium	21H	1	12	1	1
	Tritium	31H	1	23	1	2
Oxygen	Oxygen-16	168O	8	16	8	8
	Oxygen-17	178O	8	17	8	9
	Oxygen-18	188O	8	18	8	10
Carbon	Carbon-12	126C	6	12	6	6
	Carbon-13	136C	6	13	6	7
	Carbon-14	146C	6	14	6	8
Chlorine	Chlorine-35	3517Cl	17	35	17	18
	Chlorine-37	3717Cl	17	37	17	20
Sodium	Sodium-23	2311Na	11	23	11	12
	Sodium-24	2411Na	11	24	11	13

7)  Electron Arrangement In Atom

1. We have learnt that electrons occupy orbits with definite energy level of an atom, as suggested by Neils Bohr.
2. These orbits with definite energy level are known as the shell.
3. Every single shell is capable of holding up to certain amount of electrons.
4. The first shell can hold up to two electrons. This is called a duplet.
5. The second shell can hold up to eight electrons. This is called an octet. 
6. The third shell can hold up to eighteen electrons.
   
7. However, with the third shell, when eight electrons are present, extra stability is gained. The additional electrons go into the fourth shell before the third shell is completely filled.
8. The way in which the electrons are distributed in the shells of an atom is called the electron arrangement of the atom
9. The examples below show the electron arrangement of some elements:

Atom	Notes	Electrons Arrangement
	Lithium has 3 protons and 3 neutrons and three electrons as well. All the three electrons are arrange as follows: Two electrons are filled in the first shell. One electron is filled in the second shell. The electron arrangement of carbon is 2.1	2.1
	Chlorine has 17 protons and 18 neutrons and 17 electrons. All the three electrons are arrange as follows: Two electrons are filled in the first shell. Eight electrons are filled in the second shell. Seven electrons are filled in the third shell. The electron arrangement of chlorine is 2.8.7.	2.8.7
	Calcium has 20 protons and 20 neutrons and 20 electrons. All the three electrons are arrange as follows: Two electrons are filled in the first shell. Eight electrons are filled in the second shell. Eight electrons are filled in the third shell. Two electrons are filled in the forth shell. The electron arrangement of carbon is 2.8.8.2.	2.8.8.2

Table below shows the arrangement of electrons of the first 20 elements in the periodic table. We shall learn periodic table in chapter 4.

Element	Proton Number	Number of Electron	Number of electron in				Electron Arrangement
			1st shell	2nd shell	3rd shell	4th shell
Hydrogen	1	1	1	0	0	0	1
Helium	2	2	2	0	0	0	2
Lithium	3	3	2	1	0	0	2.1
Beryllium	4	4	2	2	0	0	2.2
Boron	5	5	2	3	0	0	2.3
Carbon	6	6	2	4	0	0	2.4
Nitrogen	7	7	2	5	0	0	2.5
Oxygen	8	8	2	6	0	0	2.6
Fluorine	9	9	2	7	0	0	2.7
Neon	10	10	2	8	0	0	2.8
Sodium	11	11	2	8	1	0	2.8.1
Magnesium	12	12	2	8	2	0	2.8.2
Aluminium	13	13	2	8	3	0	2.8.3
Silicon	14	14	2	8	4	0	2.8.4
Phosphorus	15	15	2	8	5	0	2.8.5
Sulphur	16	16	2	8	6	0	2.8.6
Chlorine	17	17	2	8	7	0	2.8.7
Argon	18	18	2	8	8	0	2.8.8
Potassium	19	19	2	8	8	1	2.8.8.1
Calcium	20	20	2	8	8	2	2.8.8.2

8) Valence Electrons

Valence electrons are the electrons in the outermost shell.

1. The electrons in the outermost shell of an atom are called valence electrons.
2. The valence electrons have great significance in determining the chemical properties of an atom.
3. Elements with the same number of valence electron have the same chemical properties.

Example:
Given that a sodium atom has 11 protons 12 neutrons. Find the number of valence electron in a sodium atom.

Answer:

For an atom,

Number of electrons = number of protons = 11

Electron arrangement of sodium = 2.8.1

Therefore, sodium has 1 valence electron.