1. How can this plant digest a frog?

2. Chap 2.1 Notes - Atoms, Ions, and Molecules Matter – is anything that has mass and takes up space. The basic unit of matter is the atom. - Nitrogen (N)

3. Structure of the atom Nucleus: center of the atom. Contains: (+) : proton (0) : neutron Electron Shells – space around nucleus where electrons travel. Contains: (-): electrons

4. Oxygen atom (O) Nucleus: 8 protons (+) 8 neutrons outermost energy level: 6 electrons (-) inner energy level: 2 electrons (-)

5. Elements – are pure substances whose atoms all have the same number of protons. The atomic number of an element is equal to the number of protons in its atoms. Number of (+) = Number of (-) The atomic mass of an element is a sum of the protons and neutrons in the nucleus of the atoms of that element.

6. Atoms are most stable when the outer electron shell is filled. If this shell is not filled then the atom will undergo bonding to form a compound.

11. Compounds: Compound – substance composed of atoms of different elements that are chemically combined. Ex. H2O Characteristics of compounds: 1.) Proportions of atoms are fixed. H2O (water) = 2 hydrogen atoms: 1 oxygen atom H2O2 (peroxide)= 2:2 ratio of atoms 2) Properties of compound differ from the elements that compose it. Ex. NaCl – Sodium; Chlorine

12. Carbon Dioxide

13. Bonding: Bonding – is a chemical reaction between atoms to create compounds. 2 Types of Bonding 1) Covalent – the sharing of 1 or more pairs of electrons between two atoms. 2) Ionic – attractions between oppositely charged ions – involves the gain or lose of electrons. An ion is an atom that has gained or lost one or more electrons.

14. covalent bonds Oxygen atom (O)Carbon atom (C)Oxygen atom (O) Carbon dioxide (CO 2 ) Covalent Bond

15. Ionic Bond: Sodium atom (Na)Chlorine atom (CI)Sodium ion (Na + )Chloride ion (CI - ) Na loses an electron to CI ionic bond gained electron

16. Chap 2.2 Notes – Water, Mixture, and pH: 70 – 95% of an organism’s mass is water. Metabolism tends to occur in a water (aqueous) solution. Why is the water you drink absolutely necessary?

17. Structure of Water and Its Polarity: Oxygen – partial negative charge Hydrogen – partial positive charge H and O are covalently bonded. In water – oxygen is “selfish” and does not share its electrons equally with hydrogen. Because of this - water is a polar compound - the molecule has an uneven electrical charge. Ex) Water acts like magnet with a “+” and “-“ pole.

18. Water Molecule O HH _ ++

19. When two water molecules get close together, a weak attraction occurs called a hydrogen bond. Properties of Water Cohesion – water “sticks” to other water molecules. Adhesion - Water can also be attracted to solid surfaces High surface tension – water has a force at its surface. ex) water bug Expands when it freezes – solid water is less dense and floats. Universal solvent – dissolves ionic and polar substances

20. Mixtures Substances that do not bond chemically and are physically separable are called mixtures. Ex) salt/sand; lead/iron; salt/sugar Salt water is an example of a solution, a mixture in which one substance evenly distributed in another. Solute – salt – being dissolved by water. Solvent – water - doing the dissolving. Water is the UNIVERSAL SOLVENT !

21. pH- Acidity or alkalinity pH – is a measure of the acidity or alkalinity of a solution. 1 7 14 Acids Bases Neutral Acid – is a substance that releases hydrogen ions (H + ) when dissolved in water. Base - is a substance that removes hydrogen ions (H + ) when dissolved in water.