2. Aim: What is matter? I. Matter – anything that has mass and volume. A. Atoms - A unit of matter, the smallest unit of an element, having all the characteristics of that element and consisting of a dense, central, positively charged nucleus surrounded by a system of electrons. 1. Nucleus – contains protons (+ charge) and neutrons (neutral or no charge). 2. Electron cloud – contains electrons (- charge) that move (orbit) rapidly around the nucleus.

4. B. Element - A substance composed of atoms having an identical number of protons in each nucleus. Elements cannot be reduced to simpler substances by normal chemical means.

5. 1. Elements are classified according to the number of protons (atomic number) in the nuclei of the atoms. a. Hydrogen has only 1 proton. Oxygen has 8 protons. Carbon has 6 protons.

6. 2. Important biology elements: a.Carbon (C) d. Oxygen (O) g. Sodium (Na) b.Hydrogen (H) e. Phosphorous (P) h. Potassium (K) c.Nitrogen (N) f. Sulfur (S)i. Iron (Fe) C. Molecule - a group of like or different atoms held together by chemical forces. O2O2 H2OH2O

7. d. Compound – a substance that consists of molecules made up of two or more elements. Examples: water (H 2 O), Carbon dioxide (CO 2 ), and Glucose (C 6 H 12 O 6 ). 1. Chemical bond –holds the atoms in a molecule together. Bond through electrons. Double bond Single bond a. Covalent bond – chemical bond in which electrons are shared between atoms.

8. 1. How do the following differ from one another? O O2O2 CO 2 Covalent Bond Animation Review 2. How do we know that the Smart Board is matter? 3. What are the smallest possible subunits of the Smart Board?