1. The symbol for carbon is – ACa Bc CCA DC

1. The symbol for carbon is – DC Capital C is the symbol for carbon

2. How many protons are in an atom of sodium? A 11 B12 C23 D34

2. How many protons are in an atom of sodium? A 11 Atomic number = number of protons Atomic number = 11 = 11 protons

3.How many neutrons are there, if the mass number is 1 and the atomic number is 1? A 3 B2 C1 D0

3.How many neutrons are there, if the mass number is 1 and the atomic number is 1? D0 Number of neutrons =Mass number – atomic number Number of protons =1 - 1 = 0

4.How many electrons are in an atom of Cl? A17 B18 C35 D0

4.How many electrons are in an atom of Cl? A17 Atomic number = number of protons =number of electrons Atomic number = 17 protons = 17 electrons

5.Which of the following is a chemical formula? A H BO CH 2 O D h2o

5.Which of the following is a chemical formula? A H (element symbol) BO (element symbol) CH 2 O (chemical formula for water) D h2o (incorrect abbreviations for H and O)

6.How many different elements are in baking soda, NaHCO 3 ? A6B5C4D3A6B5C4D3

6.How many elements are in baking soda, NaHCO 3 ? C4C4 Elements: Na – sodium H – hydrogen C – carbon O - oxygen

7. Which of the following situations contains an example of a chemical reaction? AIce forming after water is placed in a freezer BWatercolor paint drying on paper CA sugar cube dissolving in a glass of water DA bicycle rusting after it is left in the rain

A Incorrect. Water freezing is an example of a physical change...liquid to solid. BIncorrect. Paint drying is also an example of a physical change. CIncorrect. Dissolving is a physical change. DCorrect. Rust is a NEW substance formed when the iron in the bicycle reacts with the oxygen in the air forming iron (III) oxide.

C 6 H 12 O O 2  6 H 2 O + 6 CO 2 HCl + NaOH  H 2 O + NaCl 8. Based on the data above, which statement is not true about chemical equations? A. Products are the rearrangement of atoms from the reactants. B.There are always more atoms on the reactant side of the equation than the product side. C.The types of atoms in the products will be the same as the types of atoms in the reactants. D.The mass and number of reactant atoms always equals the mass and number of product atoms.

B. There are always more atoms on the reactant side of the equation than the product side. Wrong! The number of atoms of each type of element on one side of an equation will equal the number of atoms of that same element on the other side of the equation. - Law of Conservation of Mass = mass is neither created or destroyed!!

9. Which chemical reaction is balanced? A.C + O 2  2 CO 2 B.2 C + O 2  2 CO 2 C.2 C + 2 O 2  2 CO 2

C = 2 C = 2 O = 4 O = 4 There are the same types and numbers of atoms on both sides!

10. Which chemical reaction is balanced? A.HBr + Mg  H 2 + MgBr 2 B.2 HBr + Mg  H 2 + MgBr 2 C.2 HBr + 2 Mg  H MgBr 2

B. 2 HBr + Mg  H 2 + MgBr 2 H = 2 H = 2 Br = 2 Br = 2 Mg = 1 Mg = 1 There are the same number and types of atoms on both sides of the equation!