1. Section 2.1

2. An atom is the smallest basic unit of matter

3. What are atoms found in/what do they make up?
Turn and Talk
What are atoms found in/what do they make up?

4. The center of the atom is called the Nucleus.
Structure
The center of the atom is called the Nucleus.
It is made of protons (+ charged particles) and neutrons (no charge parts)

5. In a cloud around the nucleus are negatively charged particles called electrons.
The difference in atoms comes in the numbers of protons electrons and Neutrons.

6. Protons = the atomic number of an atom
The number of protons +the number of neutrons= Atomic Mass (Weight)

7. Answer in notebook
If an atom has a proton number 6 and a neutron number 6, what is the atomic mass?

8. Think about it…. And answer in notebook
If an atom has an atomic mass of 15 and a neutron number of 8, What is the number of protons?

9. Elements
Elements are one particular type of atom that can not be broken down into simpler substances

10. Isotopes are atoms that have different numbers of neutrons.
Scientists refer to isotopes by their name and the number of protons and neutrons they have.
For example: carbon 12, 13 or 14

11. An ion is an atom that has lost or gained electrons (charged)
Ionic Bond: Force between oppositely charged atoms
Covalent Bond: When atoms share a pair of electrons

12. If an atom has lost 2 electrons, what will the charge of the atom be?
Turn and Talk
If an atom has lost 2 electrons, what will the charge of the atom be?

13. A compound is a subtance made up of atoms of different elements bonded together in a certain ratio.

14. A molecule is two or more atoms held together by covalent bonds.

15. Just checking to be sure your with me….
All molecules are compounds and all compounds are molecules.
True or False
Explain!

16. Electrons travel around the nucleus in regions called energy levels.
Each level has a particular capacity
Each level grows in capacity as they go up.

17. The levels
1st= 2
2nd= 8
3rd= 18

18. Answer in notebook.
If an atom has 16 electrons, how will they be placed in each energy level?