1. STAAR Review Category 1-Matter & Energy Students demonstrate an understanding of the properties of matter and energy and their interactions.

2. Key Terminology Conductivity Density Luster Malleability Metals Metalloids Non-metals Valence - ability to transfer heat and/or electricity - measure of a materials mass per unit volume (m/v) - describes how a material reflect light - materials flexibility without breaking - good conductors of heat/electricity - poor conductors of heat/electricity - have properties of both metals & nonmetals - # of electrons in the outer most shell of an atom; - determines the reactivity of an element 8.5A; 6.6A

3. Do you know? Element is Compound is Mixture is a substance that cannot be broken down into simpler substances. two or more elements combined to form a new substance whose characteristics are different than the original elements. two or more substances that are not chemically combined and can be separated. 6.5C

4. Common Elements & Compounds… He N C S P Ca Cl Si H 2 O CO 2 NaCl C 6 H 12 O 6 CO HCl CH 4 Helium Nitrogen Carbon Calcium Chlorine Silicon Water Carbon Dioxide Sodium Chloride (salt) Glucose (sugar) Carbon Monoxide Hydrochloric Acid Sulfur Phosphorus Methane 8.5D; 7.6A

5. Atom Structure atom electron cloud nucleus protons * positive charge * mass = 1 AMU neutrons * NO charge (neutral) * mass = 1 AMU electrons * negative charge * mass=0.005 AMU (  0) 8.5A

6. The Atom * negatively charged * mass = 0.005 AMU * positively charged * mass = 1 AMU * no charge (neutral) * mass = 1 AMU protonsneutrons * protons + neutrons = Atomic mass 8.5A

7. The Element Cube Element Symbol Atomic Number (# of P + ) Atomic Mass (avg. # of P + + N 0 ) Element Name 8.5C

8. Periodic Table Nitrogen Family Period 6 What is a row called?What is a column called? What do all members of a family have in common? What do all members of the Helium family have in common? *** Same # of valence e - ; same reactivity *** *** Noble gases; non-reactive *** Every element in a Period has the same number of energy levels (or orbitals or electron shells) This is the Nitrogen Family OR Group V (15): There are 5 VALENCE electrons in every element in this group.

9. How many… Molecules –2–2 Elements –3–3 Atoms –4–48 2C 6 H 12 O 6 Molecules –3–3 Elements –4–4 Atoms –4–45 3Ba(CH 3 COO) 2 3Ba(CH 3 COO) 2 8.5D

10. Chemical Reactions & Equations Hydrochloric Acid + Sodium Hydroxide  Sodium Chloride + Water HCl + NaOH  NaCl + H 2 O Is this equation balanced? H = 2 Cl = 1 Na = 1 O = 1 H = 2 Cl = 1 Na = 1 O = 1 YES, it is balanced. 8.5E

11. Question In the diagram, which cools off more quickly? A. the land B. the water C. neither D. not given 6.9C