1. All substances are made from atoms.
There are about 100 different types of atoms
An element is a substance which contains only one type of atom
Atoms

2. The Periodic Table
The Periodic Table

3. Element, Compound, Mixture

4. Atoms have a small central nucleus containing protons and neutrons
Structure of an Atom
Atoms have a small central nucleus containing protons and neutrons
Electrons orbit the nucleus
Protons, neutrons and electrons have different masses and charges
Structure of an Atoms

5. Atomic structure
Atomic Structure

6. Atomic structure
Atomic Structure

7. The atomic number is the number of protons in the nucleus
In an atom, the number of electrons always equals the number of protons
Atoms do not have an overall electrical charge
Atomic Number

8. Atomic number
Atomic Number

9. The mass number is the total number of protons and neutrons in an atom
The number of neutrons can be calculated by subtracting the atomic number from the mass number
Mass Number

10. Mass number
Mass Number

12. Calculations
Calculations

13. Isotopes have the same atomic number but different mass numbers
Isotopes are atoms of the same element that have different numbers of neutrons (e.g. carbon-12 and carbon-14)
Isotopes have the same atomic number but different mass numbers
Isotopes

14. Isotopes
Isotopes

15. Each electron in an atom is at a particular energy level (or shell)
Electrons
Each electron in an atom is at a particular energy level (or shell)
Electrons fill the lowest energy levels first (nearest to the nucleus)
The first shell can take a maximum of 2 electrons, the second shell can take 8, and the third shell can take 8
Electrons

16. Electron Shells
Electron shells

17. Energy Level (Shell) Maximum electrons Number of Orbitals 1st 2nd 3rd
Questions
What is an orbital?
What are valence electrons?
When is an atom stable?

18. Electron arrangements

19. H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar

20. Wordsearch
Wordsearch

21. Quiz
Quiz