Begin with chemistry - Gallium Powered

As you see in the center is the core containing the protons and neutrons and the other part is the place where electrons can be. As we go further from the core the chance of an electron being there becomes smaller when it finally reaches zero.

If you are interested we can tell you that in reality, this chance is never zero. An electron can travel the distance, from where you are right now, to the end of the Universe and return to its home even if this is very unlikely to happen because electrons tend to be closer to the core.

It is difficult to wrap your head around so much information so we offer you a different approach.

Let’s imagine you have a stadium in front of you with a soccer pitch, one ball, and one footballer. So the ball will be the core of the atom. The player will be one electron and the field will be the place where this electron can move. As everything is only one of a kind we can agree that this is the element hydrogen.

The footballer can move anywhere but he is bonded to the ball. He is free to make everything but the game is such that he needs to be around the ball. Note that in this case, the footballer as an electron is bigger than the ball but in reality, the core of the atom is bigger and weighs more. We cannot predict where he will go, and it is the same with atoms. We cannot predict where the electron might go.

When we compare the whole playground with the ball and the player we can see how much empty space there is. It is the same with atoms too. Most of their space is empty which is not really empty but that is too much information for just one lesson.

Next, you need to know that elements have an atomic number and mass number. All elements are arranged by their atomic number in the periodic table which we get by counting the protons in their cores. The mass number is formed when we add the number of protons to the number of neutrons.

Elements have isotopes. To summarize all isotopes of an element have the same amount of proton because if they have more or less they will become a different element, but some have more or fewer neutrons which make the difference in their mass number.

Most of the things atoms do are all about their electrons. Let’s see why:

Most atoms are not happy naturally so they need to play with others to become happy. It is all about the last layer of every electron shell. When an atom has all slots in its last layer filled it is happy (We talk about the low energy level they tend to achieve). Most elements do not have the privilege to have their last layer filled so they need to play with others. Of course, there are exceptions which we call noble gases.

They have everything they need and do not play with other elements. They do not react under normal conditions since they are stable and happy.

Scientists believe the outer shell is so important that we actually have a name for it – the valence shell. And only if this shell is filled with electrons the atoms are stable (happy).

Let’s go back to the stadium we talked about earlier this lesson. This time we will play a game in it. But this game has a goal and a rule. The game will be about selling tickets for the stadium’s seats. The rule will be to sell tickets for the places which are closest to the field first. The goal is to fill the whole stadium (in the case with atoms to fill all shells/layers).

In this stadium the first layer will have 2 seats, the second will have 8 seats and the third one will also have 8 seats (yeah, a really small stadium). In the first case, we have sold only one ticket which means our atom has only one electron. But the first layer has 2 seats and one of them is empty. This saddens our atom.

This is the case with hydrogen atoms. They have one proton which allows them to possess only one electron but they want two. So every hydrogen atom bonds with another hydrogen atom and they share their electrons in a way both have their outer layer filled.

Imagine this element is not hydrogen and instead of one proton, it has two. In this case, it will have 2 electrons too, and this makes its outer shell filled. The element is happy. This element is helium which is a noble gas. As we mentioned before only noble gases are happy as they are and do not play with others.

If you look closely at the periodic table you will notice that elements from the same group have the same valence shell. This is why they behave similarly.

We owe a lot to the scientist Gilbert Lewis and his Lewis dot structure. We use his structure to draw the electrons of the valence shell of every element as dots around the symbol of the element. It makes things easier for sure.

To be easier for you to draw these dots follow this tip – start from the top of the element by placing one dot on every side clockwise.

This was a lot of information so let’s try to summarize it – a big part of the stuff in the Universe is made out of matter which has four states (solid, liquid, gas, plasma), this stuff is made of elements and currently, we have discovered 118 but only 92 occur in nature and 25 are essential for life.

Atoms are the particles that build up every element. They are made of protons, neutrons, and electrons which are made of quarks and gluons. Atoms are very small and very complicated. Most of the things they make are about their desire to have filled outer electron layers which we call valence shells. Some atoms are noble and have their outer shell filled by default and do not interact with others.

And even shorter – chemistry is the science that explores the chemical elements and their compounds. It is called the central science because it is located between physics and biology and gives them fundamental knowledge about the fields they explore.

This is all for this lesson. But the adventure yet begins. We recommend you take a break before going to the next lesson. See you soon!

We will begin by telling you that chemistry is everywhere but you already know this. But why is it true? To summarize, everything we see is made out of matter. Of course, there are exceptions. Many things in the Universe are not made of matter but for the purposes of this lesson, we will ignore them.

The matter has four states - solid, liquid, gas, and plasma. Here on earth, the fourth state of matter cannot exist for a long period of time. We see it when lightning strikes, some people are lucky to see the Polar Lights, and maybe you are even reading this lesson from a plasma screen. Let’s see what we know about these states of matter.

In solid-state atoms are compacted tightly and will definitely resist you if you try to change their shape. They have volume and shape.

Liquids on the other hand do not have shape. They only have volume. Unlike in solid-state here, molecules have more freedom to move, which is why they can adopt the shape of the container they are poured in.

Gases do not even have a volume of their own. In a gaseous state, molecules are held by weak bonds that easily break. They occupy every bit of the space they have available. Particles in this state move freely and catholicly.

Plasma is a state of matter in which the electrons, of the particles that the plasma consists of, are forced to leave their atoms due to extreme conditions (temperature).

Plasma is so intriguing that it deserves a lesson of its own so we will leave you with this for now.

Now when we know what matter is and most things are made of it we can focus on its building blocks – the atoms.

The model of the atoms most of us are familiar with is indeed incorrect. But we still use it as atoms are so small that it is the easiest way to understand and visualize them.