Balanced chemical equation

On the 14th December, me and Samnang Hor taught a junior STEM class about balancing chemical equation. So we come up with some fun activities for them to practice like using the simulation and also Kahoot. We start off by trying to understand what they have learned than explain them why do we need to balanced chemical equation. We need to balance the chemical equation because the mass of the atom can’t be created nor destroyed according to the law of conservation of mass.

+  The plus symbol connects the first substances and the final substance. (seperate two reactants or products)

→  Identify the chemical reactions into products. Or chemical change or produce.

Reactants are the starting materials in chemical reaction. The substance that go through changes during the reaction. The substances on the left side of the arrow are called reactants.

The substances on the right side of the arrow are called products.

Can’t write # 1 as the coefficients but just put a blank there. Example: O2
Balancing chemical equation

Link to the presentation :

Chemistry round 2

We been learning and using the periodic table for awhile now. There are many topics in chemistry we been covered. This round we focus more on drawing lewis dot structure that related to elements, atoms, compounds. Than we learn about the octet rules and formal charge. Element that are on or under the 3rd row in periodic Table can hold up to 10 electrons breaking the octet rules.

Lewis dot structure → shows bonding between atoms


Li ⇒  is Lithium and it have 1 electrons

Octet rules atom wants to have eight valence electrons in its outermost electron shell to become like a noble gas so, it combine with other atom and share electrons.


H2O ⇒ is an chemical formula stand for water

H: 1 electrons & O: 6 electrons = 8 electrons

*This sign    stand for 2 electrons*

Formal charge ⇒ the charge that are assigned to an atom, assuming that electrons in bonds are shared equally between atoms.

Equatione: (# valence electrons) – (# valence electrons in bonded atom) = 0


H = 1 e        1 – 1 = 0 *True*

O = 6 e        6 – 6 = 0 *True*

*Because it share electrons that why we count only 1 of the electrons that they are holding to.*


We were learning about geometry and most specifically about transformation, Congruence, Similarity, and Right triangle & trigonometry. So we are using Khan Academy to help our guild through this topic because the in the textbook it doesn’t demonstrate and give examples much. For each level, we reach we got 4 points and there is 6 level which is mastering it but the teacher expected us to get to level 5 and we will have 20 points. However, if we have any questions we can screenshot it, and then we will go over it in class together. By doing this it allows us to go at our own pass and not rushing through to gets point but actually understanding it. Moreover, it gives students the opportunities to take more responsibility and show that they use their time wisely.  


  • Rigid: maintain and produce congruent shape
    • Translation: vertical and horizontal shifts
    • Rotation: it’s rotate in a certain degree.

270 / -90 degree = x,y   y,-x

-270 / 90 degree = x,y  -y,x

180/-180 degree = x,y  -x,-y

  • Reflection: line of reflection and it’s a mirrored image


  • Dilation: It have the similar shape but different size and it’s scaleable and it’s angle is the same.

Congruence – equal size and shape

Similarity – same shape in term of ratio

Right triangle & trigonometry

Sin = Opposite over Hypotenuse

Cos = Adjacent over hypotenuse

Tan = Opposite over Adjacent

Law of sin = > sin (a) over a = sin (b) over b = sin (c) over c

  • If you have 2 angle and 1 length use it to find another length
  • If you have 1 angle and 2 length use it to find another angle

Law of cos

=> a² = b²+c² * – 2bc cos(o)

=> b² = a²+c² * – 2ac cos(o)

=> c² = a²+b² * – 2ab cos(o)

  • If you have 2 lengths and an angles use it to find another length
  • If you have 3 lengths use it to find an angles
  • a, b, c  representing the lengths

Math round 1 of 2018-2019

For this round we were working on SAT prep. So basically, we continued focus on SAT but this time in class we wrote down what we haven’t learn and within this year our teacher will teach us a few of those topic. This round we learn about imaginary number, complex number, functions and quadratic. For function and quadratic we learn and practice in Khan Academy algebra 1.

Imaginary number ⇒ i

i = √-1

i^2= -1  

i^3= -i

i^4= 1

Complex number ⇒ a +bi

a = real number

bi = real number times by imaginary number

Example: 5+2i

* imaginary function


Example: 5/3i  ⇒ 5/3i  * 3i/3i ⇒ = – 15i/9

*multiplying by the conjugationa doesn’t have to be the same

a/(b + i )⇒ (a/(b + i)) × ((b – i) ÷ (b – i)) ⇒ (a – bi) ÷ (a – bi²)  (± a – bi) ÷ (b)


4 ÷ (9 + i) ⇒ (4 ÷ (9 + i)) × ((9 – i) ÷ (9 – i))  ⇒ ((36 – 7i) ÷ (81 – i²)) ⇒ ((36 – 7i) / 82)

Density of the coin

Last year in science class we learned about physic and this year we are learning about chemistry. I don’t like the chemistry but now I feel it’s just like physic so I can relate too a lot. First off we need to draw the classroom in order for us to be safety and know where everything is place. In Order to be safety, when we are doing a lab we need to have safety glasses, lab coat and sneaker to cover up your feet. After learning for a week start with a lap which is about the density of the coin. It was a pretty good experiment because we get to do it individually and there are variety of coins that we can choice from. For our lab notebook in there we need to write our own hypothesis, procedure, data, analysis and conclusion.


SAT Bootcamp

At the Beginning of this school year, the 6th of August, we had an SAT Bootcamp. Most SAT Bootcamp would last about two months nevertheless we had tights schedule so we did it for two weeks. There are two mentors Kim, a recent Princeton grad in Computer Science and Amada, an ESL teacher from an all-girls school in New Jersey.

So during the day, we would have 2 hours of each class math, literacy and study hall time. In math class, we learn how to pick and use an equation efficiently. On the other hand, in literacy class, we work on reading and Writing and look through what type of questions are there. As usual every day we would get 10 to 5 pairs of mostly confused words and as homework, we need to write sentences that related to us individually.

Moreover, during the Bootcamp, we would get a lot of practice. Furthermore, we in the Bootcamp we took a test on khanacademy SAT at the beginning middle and end to see how much we grow and does all of the strategies that the mentor teach us helpful. The mentor doesn’t expect that use everything we learn for the khanacademy SAT test because there are too many rules to follow just step by step first. At the beginning of the test, I get the score of 930 then 940 and lastly 980. I feel like I didn’t improve much in these past two weeks but still, I have learned a lot from them. By joining this SAT Bootcamp it really helps me to become a better learner and uses resources all around me.

Khmer MUN

On the 23rd of May, all of the senior students were given an opportunity for the whole day to joined Khmer MUN (Model United Nations). We are the first school in Cambodia that did this and possibly next year we will invite others school to join us. I was scared at first because I didn’t have a lot of time to research and prepare myself for the topic as well as my first time joining it. I was the delegate of Russia and the debating topic is called “Biological Weapons of Mass Destruction.” It was a big topic for the starter to research but we did our best to make our teacher proud. 

When I first read my opening speech it was scary than I started to take a deep breath and prove to everyone that I can do it with confidence and loud voice in myself. I mostly focused on my opening Speech not finding a resolution, which had affected me in my debate. Lucky my teammate they have a lot of resolution so our team decided to use one resolution and then make some edit to it. After all, I have learned that you and your team doesn’t need to agree on the same resolution at all and talk more, be confident in yourself no matter what. Even Though It was my first time I took a risk to delete one of the other team resolutions since they didn’t have enough information to prove that it should stay there.

Moreover, I would like to says “Thank you to all of the Khmer facilitators for giving me this opportunity to practice my Khmer and also inspired me to join an event like this more.” After joining this event, it inspired me to will join MUN in ISPP for next year and I can’t wait to join it. Most of the students were told that English was easier than Khmer because we don’t have to spend time translating information. Inconclusive, if I had never joined this Khmer MUN I would never make my mind and join MUN.  



Video Link:                       

The story of a Superman!

In physic class we have a project called superheros. In there we have to write a story and also create a poster of any superheros about the superheros, powers and compare it to real physics life. On Monday in class we will do a gallery walk of all of the superheros we been researching on.

          Let’s take a look at the sky! It’s a bird, it’s a helicopter, it’s a plane, it’s a SUPERMAN! He can fly, he’s indestructible, he’s is strong and he saves our life! Moreover Superman is a superhero and his superpowers are Invulnerability, Vision, Hearing, strengths, leaping or flying and super Breath. But, how is Clark Kent able to accomplish all of these amazing things that required superpower skills? On the other hand, human can’t have these special abilities like superman so what is the science behind his special abilities and him?

The story started, He was born in this planet called Krypton that orbits around a red star. Krypton was much heavier than the earth which make it clear that the bigger the mass is the higher its gravitational force is. If we look closely, this means that superman on earth is able to fly or jump high because of the small gravitational pull from the earth to him. Krypton planet was destroyed result due to the internal pressures that Krypton’s get. Kal EI (birth name) was send by his father called Jor-El in a small rockets to the earth.

As Kal El grow older, He was raised by his adoptive parents in earth. He was known for Clark Kent who has been shown as superman second personality. Superman was strong and could jump from a building to another and doesn’t required pushing from the ground. He use this power called telekinetic power the ability to move a objects at a distance by mental power. Newton’s Second Law stated “there must be some upward force to balance the downward force of the weight.” So this means that he must use some type of upward force that is higher than his weight in order for him to fly. The yellow sun (our sun) that allow him to fly. He gets energy from electromagnetic radiation which contain in the light of our sun. He also could survive in space, due to his lungs clearly aren’t needed for respiration. Superman metabolize energy from the earth sun light (like human metabolize energy from food) that will allow him to use when he need to fly or jump off from one building to another. Moreover he can stored more than the amount that needed to use for his ability can and also convert this energy into very high kinetic energy. Which in the future will allow him to defeat the gravitational force of our of the earth.

Hedy Lamarr – Women in STEM

On the 18th of January, we had a project to write an article about any Women in the STEM field. My article includes information about Hedy Lamarr and also her inventions that she had created.


Hedy Lamarr was born on the 9th november 1913 in Vienna, Austria, the daughter of a wealthy jewish banker. She drop out of school just because she want to pursue her dream, which is to become an actress. In her film career, she had become a Hollywood star in 1940s and she was essentially the equivalent of Angelina Jolie. Hedy Lamarr was once known as the most beautiful woman in the world.

There is no record of Hedy Lamarr talking about her invention to the reporters. Her invention is call “Frequency hopping” and she work on this inventintion with George Antheil. In her off hours, from work she work on this creation.There’s a lot of rumors about her invention. Some says “She is too beautiful, to come up with this brilliant idea.” What I learn from her is that you don’t have to have a high school degree to invent something. What you need is your brain and dot connection. The more you connect ideas from various people the more you can improve your invention. Hedy Lamarr created her device in world war II to assist secret communication, and it also served as an essential building block for wifi, bluetooth and GPS. That we now use these type of thing everyday and we don’t even realize who was the inspiration for these people to create Wifi, bluetooth and GPS. Hedy Lamarr has no science training but have a exceptional scientific mind. She always took things into her own hands and never let anyone control her. She talked to the navy about her invention with George Antheil and provided 7 millions dollars to the USA for the selling war bond. The Navy didn’t us her invention at that time but they it after world war II.

When she grew old, she finally received recognition but she can’t get out of her house. However, she was still able to send voice message to everyone by the news saying thanks you. Hedy Lamarr and George Antheil applied for the patent for her invention on 11th August 1941 under her marriage name “Hedy Kiesler Markey” with a co-founder George Antheil. Then she was honored by Electronic Frontier Foundation in 1997 for her invention. During her life she was quoted as saying “Any girl can be glamorous. All you have to do is stand still and look stupid.” While she was certainly glamorous, as proven by her invention, she was most certainly not stupid.

Behind the mask: Effects of Makeup Usage on Young Teenager

In literacy class, we had a project to write like a newspaper about any topics that is gender equity based. My topics was about the effectiveness of makeup on young teenager.


Imagine this, If you were the person who wore make up everyday, it doesn’t matter thick or thin, someone asks you why do you have to wear makeup everyday? How would you answer this? Some people said  that they wear it to feel confident but the real reason is they feel less confident without makeup.

Liking yourself and being  happy are good, makeup is just an add on. People who routinely wearing makeup everyday are often less confident. Makeup is like a mask that hides the real you.  Soon putting makeup on will become part of your daily life. The confident you have in yourself will soon diminished.

Dear young teenagers, I know you want to be beautiful; however, sometimes we have to accepted the fact that everyone is beautiful in the way they are. Learn to love yourself, if you don’t love yourself, who will? Please take a look in the mirror every morning and your will realize how beautiful your face is without it. According to an article they stated, “But really, we’re all beautiful to someone and makeup can just be the icing on an already okay cake.”

You might think that makeup is a way to look more attractive but actually you not. Some men don’t expect their girlfriends to wear makeup, nowadays what you look like makes people love you just the way you are, Not that mask that you are wearing everyday, girls.

Do you ever want to wear makeup as soon as possible just like a grown up women’s? Again, please take a look in the mirror and look at your face; tell yourself everyday how beautiful you are and realize how much your face shines by itself. You don’t need makeup to be happy and to start your day. You may be tired of wearing makeups early and spent most of your morning just to look beautiful. But, what you natural look now is what older generations are trying to get back later in their life.