Acids and Bases

What are Acids and Bases? How do they act in daily life?

Acids and bases are our main courses during this journey of the class. We have read the article in CK12 to understand more about them. They look definitely similar but somehow they are different. Then, what are they?


Therefore, what is an acid, so acid is an ionic compound that creates positive hydrogen (H+) when dissolved in water. Sour taste is the property of acid, which all sour tastes are acid such as lemon, orange and more (warning: Never taste an unknown substance ). Moreover, the acid also conducts electricity because it consists of charged particles in the solution. Acid is also important in the world because some products contain acid. For example, sulfuric acid is used to manufacture many products such are paper, paint, and detergent. There is also a way to detect acid, which we use an indicator. An indicator will change the color when acids come to contact with. An example of the indicator is a compound named red cabbage. Red cabbage is a liquid chemical that will changes the color depends on how much acid contain in some products including vinegar, sodium bicarbonate, bleach and more. You can also try to test the acid in your drinks too like coca cola, or sprite. While pouring the red cabbage indicator in another liquid, combine together will change the color. Then you can use the pH scale to notice whether how high or low is the acid in that liquid.


A base is an ionic compound that produces negative hydrogen (OH-)  when dissolved in water. Also base shares its own certain property as well, including bitter taste. All bases have bitter taste including soap, coffee and more. In addition, the base feels slippery, you can imagine how slippery soap is. Therefore, soap is also including in base. Like acids, bases also conduct electricity because they consist of charged particles in the solution. Bases incorporate in certain products including soap, bleach, and so on. We can use red cabbage indicator to detect both acids and bases.

From soapqueen

This picture shows the level of pH Scale. Under the pH of 7 are acids and above the pH of 7 are bases. 

The Cycle of the Life Element


Let’s takes a little time to look at your clothes and think what’s creating it. If you think carbon is the things that create your clothes, you are on the right track. Carbon is an element that stayed in group 14 and period 2. It is the element of life, that all matters are made of carbon. Also, it is everywhere on earth. That’s the reason why in Stem class round 3 we are learning about the carbon cycle. The carbon cycle is the process in which carbon dioxide rise up to the atmosphere by respiration and returning carbon dioxide into living tissues. Carbon cycle has 4 processes which are photosynthesis, decomposition, combustion, and respiration.

Photosynthesis is when the living organism incorporates trees absorb the carbon dioxide and create them into food for themselves.

Respiration is when the living organisms including human and animals inhale the oxygen and exhale as carbon dioxide that goes to the atmosphere.

Combustion is coming from human activity every day that burn fossil fuel and creating the gas into the atmosphere. The gas is carbon dioxide.

Decomposition is when the decomposer breaks down the dead organism and returning the carbon dioxide into the atmosphere from the body by respiration.

Carbon cycle needs to have these 4 processes. If one of those part extinct there will be too much carbon in the atmosphere that will cause global warming.


Stem Round 2


Chemical Bonding

Covalent bond is the bonding between nonmetal and nonmetal that share the valence electrons in order to be complete or stable. When the elements are stable, they won’t share electrons again because they already completed. To add on if they are completed they will have eight valence electrons and inner electrons are two. For instance, there are two elements, chlorine and chlorine. They are nonmetal groups. They each have 2 electrons inner shelf and have 7 electrons outer shelf. That’s mean they need 1 more to complete. Two of them can share one of their electrons together so each of them will have eight because they each share one electrons. Now they are complete so they won’t react with other elements. To summary the instance covalent bond can share more than one electrons in order to become stable.

Ionic bond is the bonding between nonmetal and metal. In this type of bond they don’t share means that they gain or lose valence electrons. Usually metallic gives out valence electrons to nonmetallic to become positively charge and nonmetallic that gets the electrons from metallic is negatively charge.( Example is below)


Matter and Atom

In the round 1 of Stem class, we learned about matter and atom. Matter is anything that has mass and occupied space. Atom is the smallest particle in chemical that can exist. In atom there are nucleus and electrons. And in Nucleus, there are protons and neutrons. Protons have the positive charge. Electrons have the negative charge. Neutrons have the zero charge. Even neutrons have zero charge but the number of neutrons are able to create more mas because they mass as about protons and electrons together. All the elements should have the same amount number of electrons and protons. it’s called neutral atom is when the electrons and protons are balance. Ion is when the atom losing or gain more electrons. It means that the electrons and protons are not balance. Ion has 2 types:

1. Cation is when the atoms have more protons than electrons.

2. Anion is when the atoms have more electrons than protons. Again the protons didn’t lose or gain more only the electrons that loose and gain.

Now let’s move to isotope. Isotope has the same amount of protons and electrons but doesn’t have the same amount of neutrons. Atomic number is the total number of protons. Atomic mass is the total mass of an atom. 

The picture is from Wikipedia.