Atoms and The Periodic Table

Atoms and the Periodic Table

• Atoms form everything in the universe. They are, essentially, the building blocks of life and matter. They are all organised in a table known as the Periodic Table. This slide show will tell you what atoms are, how they are arranged and how they bond. It will also tell you what the periodic table is, how to use and understand it, and what is organised in it and how it is organised.

What are atoms?

• Atoms form almost everything in the universe. They cannot be seen with the naked eye because they are so small. The only way you can see them is with a microscope. Atoms are a type of particle (A minute portion of matter) that can have many properties such as strength, melting point, and magnetism, which are usually seen in a group of atoms, known as a molecule. Atoms can bond together to form molecules.

How are atoms arranged?

• Atoms are made from three main components: Protons, Neutrons and Electrons. The way you can identify them is like this:
• Protons and neutrons are the same size: For presentation purposes only let's refer to their size as one Size Unit, or possibly SU. Electrons are much smaller.
• Protons carry a positive charge of 1, Neutrons have no charge, and Electrons carry a negative charge of -1
• The Protons and Neutrons are positioned in the middle of an atom; the electrons are arranged outside of the centre of the atom in layers known as shells
• There can only be a maximum of two electrons in the first shell, then the others can have a maximum of eight electrons in their outer shells

How and why do atoms bond?

• The objective of atoms is to gain a full outer shell with the maximum number of electrons in it. An atom with a complete outer shell is known as an ion. So, effectively, an atom wants to become an ion. They can get these electrons in three ways, which are different types of bonding. These types of bonding are: Ionic bonding, Covalent bonding and Metallic bonding.
• In Ionic bonding, atoms will steal electrons from each other. The atom with the most electrons will take electrons from an atom with the least electrons. For instance, an atom with seven electrons in its outer shell will take an electron from an atom with only one electron in its outer shell. This type of bonding only happens between metal and non-metal atoms.
• In Covalent bonding, atoms will share electrons. They will effectively be joined by the electrons they are sharing. For instance, a Hydrogen, which normally only has one electron in its only shell, atom will join with another Hydrogen atom because they will both get that one electron they need to complete their only shell.
• In Metallic bonding, metal atoms get bonded together, while the electrons in their outer shell detach and become free electrons. These keep the metal atoms together, and also enable metals to conduct electricity. Interestingly, some non-metal materials, such as graphene, are able to conduct electricity.

What is the Periodic Table?

• The Periodic Table is a table in which every single type of atom known to man is arranged. This is one of the most useful tools a scientist, student, or anyone who is involved with chemistry will ever have. It is an atomic collection of all you need to know about atoms.

How is the Periodic Table organised?

• The atoms in the Periodic Table are arranged in groups and periods. The groups show how many electrons are in the outer shell of the atoms, and the periods show how many shells the atoms have. They are also arranged in reactivity. The atoms lower down the table are not only the ones with the most electrons, but are also the most reactive. This makes Francium the most reactive because not only does it have seven electron shells, but its last shell contains only one electron, making it easy to bond with and therefore highly reactive. Each type of atom also has its own symbol, with Hydrogen referred to as H, Helium as He, and Potassium as K.

The end

• Thank you for watching this slide show. I hope you can put the knowledge in it to good use.