1. Chap 3 Section 1 Chemistry of LIfe

2. Nature of Matter Matter- anything that has mass and takes up space. Energy- ability to cause change Atom- smallest unit of matter 1. Protons (+) Charge 2. Neutrons (0) Charge 3. Electrons (-)

3. Nature of Matter Element- Something made up of only one kind of atom. Can’t be broken down into a simpler form by chemical reactions. (Oxygen, Gold, Iron, Neon) Six elements make up of 99% of living matter are: S,P,O,N,C,H.

4. Nature of Matter Compounds- made of 2 or more elements. (Water H2O, CO2,) Molecular compounds- Like water are held together by chemical bonds to form different product than what original product. H and O gas but when bonded form liquid. Ions- when atom losses or gains electrons to become charged. Opposite ions attract. HCl, NaCl, NaOH. Ions are important in sending signals through nerves to muscles to contract or expand, also for carrying oxygen throughout body.

5. Mixtures Mixture- a combination of substances in which individual substances retain their own properties.