Atoms are mostly empty spaces. The nucleus of an atom is extremely thick and contains nearly all of the mass of each atom. Electrons give very little mass to the atom ( it takes 1,836 electrons to equal the size of a proton) and reach so far away from the nucleus that each atom is 99.9% empty space. So if the atom was the size of a sports arena, the nucleus would only be the size of a pea. Even though the nucleus is much thicker compared with the rest of the atom, it's also made up of mainly empty space.
What are electrons? An electron is a very small piece of matter and energy. Its symbol is e-. the electron is a microscopic particle. It is believed to be an elementary particle because it can not be broken down into anything smaller, And sometimes it may move to the speed of light.
What is an elementary particle? An elementary particle is a particle that is not made up of any smaller particles, while all the other particles and matter in the universe are made up of elementary particles.
How many atoms are there? There are over 100 different kinds of atoms. About 92 of them are made naturally. The first new atom was made by man technetium, which has 43 protons. New atoms can be made by adding more protons to an atomic nucleus (the small, dense area that is made up of protons and neutrons at the center of the atom) But, these new atoms are shaky and rotten into smaller atoms immediately.
Atoms are very small, which is also why their name means uncuttable or undivisible. The normal atom is about one-tenth of a billionth of a meter across. The largest atom (Cesium) is 9 times larger than the smallest atom (Helium).
Elements:
What is an element? An element is a clear substance that is made from a single type of atom.
Atomic numbers: An important number in an element is the atomic number. the atomic number is a number of protons in each atom. Each element has a special atomic number. Hydrogen is the first element and has one proton, so it has an atomic number of 1. Gold has 79 protons in each atom and has an atomic number of 79. Elements also have the same number of electrons as protons.
How does an element form? Yes, all elements are made from the same type of atoms, but they come in different shapes. Depending on their temperature, they can be solid, liquid, or gas. They can also have different shapes depending on how tight the atoms are close together.
How many elements are there? There are 118 known elements, but only 94 are known to naturally exist on Earth.
Families of elements: Elements are sometimes grouped together because they have similar properties. Here are some of the types of properties:
Nobles gases: Helium, Neon, Argon, Krypton, Xenon, and Radon are all noble gases, They are special in that the outer shell of their atoms is full of electrons. This means they don't react much to other elements.
Alkali metals: These elements have just 1 electron in the outer shell of their atom and are very active. Some examples are Lithium, Sodium, and potassium.
How else can I understand elements? An important way of learning and understanding elements for your chemistry class is using the periodic table.
Chemical Compounds:
What is a Chemical Compound? Chemical compounds are formed when elements are joined by chemical bonds (it's what joins atoms together) The bonds are so strong that the compounds act like their own substance. So a compound is a type of molecule bonded with more than one element.
What is the smallest Unit in the chemical compound? Molecules are considered as the smallest unit that is possible to exist in the chemical compound.
When two or more atoms join together, we call it a molecule, just like how electrons, protons, and neutrons join together and make atoms, And when two or more atoms of different elements join together, we call it a compound.
All compounds are molecules, but not all molecules are compounds. That is because a molecule can be made up of two atoms of the same kind since two oxygen atoms join together to make an oxygen molecule. But, all compounds are made up of two or more different types of atoms.
Compounds are very common. There are just over 100 different kinds of atoms, but there are millions of different kinds of substances made up of different molecules. Probably everything you see around you is some type of compound.
When different atoms of different kinds join to form a compound, a new substance is made. New compounds do not have the same physical or chemical traits as the original elements that were used to make them. They have a life of their own.
Compounds are written with formulas that show which elements from the periodic table were combined. One common compound is water. When two hydrogen atoms (H2) combine with one oxygen atom (O), it makes the compound H2O, which is mostly known as water. All water molecules have this same combination of atoms. Water is not hydrogen or oxygen, you don't expect to put out a fire by pouring oxygen or hydrogen on it, they must join together and make water molecules, and then it will put out the fire.
Chemical bonds:
How do these compounds form? and, what holds the atoms in a molecule together? Compounds are made when elements are joined and held together by strong forces called 'chemical bonds'. These bonds involve the electrons that orbit around the nucleus of an atom.
There are two main types of chemical bonds that hold most compounds together:
Ionic bonds: these are made when one atom 'donates' an electron to another so that both will have a full outer shell, during that, the atoms are joined and create a compound.
Covalent bonds: these share electrons between atoms in order to fill their electron shells. In the compound, molecules are held together by the attraction between the nucleus and the shared electrons.
Thank you for reading, hope you learned more about atoms, elements, compounds, molecules, and more. :)
