2. Objective: What are the basic components of an atom? Do Now: Watch the video clip, answer the following question- Why do we study chemistry in biology?

3. Matter: Anything that occupies space and has mass Element: Pure substance that cannot be broken down into other substances Ex: Carbon (C), Hydrogen (H), Gold (Au) The elements that are found in all living things are: carbon (C), oxygen (O), hydrogen (H), nitrogen (N)

4. Compound: 2 or more elements chemically combined Ex. Carbon dioxide(CO 2 ), water(H 2 O)

5. Atoms atom: smallest possible particle of an element Parts of the atom (subatomic particles) Nucleus: central core of atom that contains protons: single unit of positive electrical charge (+) neutrons: electrically neutral = no charge Outside of the nucleus: Electrons: single unit of negative electrical charge (-) located outside of the nucleus

7. Atomic number: number of protons in an atom –Differentiates elements Atomic Number and Atomic Weight Atomic Weight (Mass number): # of protons + # of neutrons

8. Carbon Potassium Atomic Weight (Mass number): # of protons + # of neutrons

9. Protonselectrons protonsneutrons Symbol Element Atomic # Atomic mass