1. What is special about water? (lab) Properties of Water

3. The study of the chemical makeup of everything. The study of chemicals made ONLY by living things.

4. The basic unit of matter that makes up EVERYTHING! Atoms have 3 parts: Proton- + Neutron- no charge Electron- -

5. Examples: Carbon (C), Oxygen (O), Hydrogen (H), Sodium (Na) *One CAPITAL letter = 1 atom

6. Isotopes- Have same # protons, but different # neutrons Radioactive Isotopes- Atoms whose nuclei break down at a predictable rate, giving off neutrons over time. Example- Carbon 14 How do we use this?

7. groups of different atoms bound together, called COMPOUNDS. Bond holding them together is stored ENERGY

8. Multiple atoms found BOUND together by chemical energy - often because the atoms are sharing their electrons Examples: - water H 2 O - salt NaCl - carbon dioxide CO 2 - glucose C 6 H 12 O 6

9. Some compounds don’t share electrons evenly. Because of this, parts are slightly positive or slightly negative. This makes them stick together like sides of a magnet. WATER IS POLAR!

11. H 2 O: Water is made of 2 Hydrogen atoms and 1 Oxygen atom OHHOHHH

12. Polarity of Water- the uneven sharing of water’s electrons OHHOHHH More Electrons - charge Less Electrons + charge

13. Hydrogen bonds- bonds holding water to other water *polar molecules will be attracted to other polar molecules, but DO NOT like non-polars (think water and oil). OHHOHHH OHHOHHH + -

14. Surface tension- Because water molecules stick together, the molecules form a barrier at the surface that, as a force, act to keep things out Ex- belly flop! OHHOHHH More Electrons - charge Less Electrons + charge

15. pH- Measuring the H+ (hydrogen ion) concentration in a mixture. Acids- A compound giving off H+ in a solution. pH <7 = acidic Bases- Compounds giving off OH- in a solution (creating lower concentrations of H+). pH >7 = basic

16. What is one way that water’s sticky properties help life exist? (lab) Properties of Water