1. List the indicators of chemical change
Formation of a gas, formation of a precipitate, change in color,
absorbtion/release of heat
2. Define
a. chemical changes – a change that alters the identity of a substance…
examples rusting, fermenting, digesting
b. Law of conservation of mass – mass or matter cannot be created or
c. Independent variable- the variable that is intentionally manipulated by the
d. Dependent variable- the variable that changes as a result of the changes to
the independent variable
e. Control- a group in which the independent variable is not manipulated, used
for comparison
f. Hypothesis- a possible explaination for observations, a testable idea
g. Mole- the amount of particles in 12g of Carbon-12, also, the amount of
substance having 6.022x1023 of any kind of particle
h. half-life- the amount of time required for ½ of the mass of an isotope to decay
i. metalloid- those elements that have properties of both metals and nonmetals
j. Ionization Energy- the amount of energy required to remove one valence
electron from an atom and form a positive ion
k. Ionic Bond- a bond between a positive and negative ion, in which electrons
were transferred between the two atoms and they are being held together by
an electrostatic attraction
3. What is the mass number of an atom that contains 29 protons, 29 electrons, and
36 neutrons?
the mass number would be 29 + 36 = 65
4. What experiment was done to discover the nucleus? Who performed it? What
experiment was done to discover the electron? Who performed it?
the gold foil experiment was done by Rutherford to discover the nucleus.
Thomson did the cathode ray tube experiment to find the electron.
(Thomson’s came first)
5. Draw Thomson’s model of the atom.
plum pudding model…a positive zone filled
with small, negative particles.
6. Which of the atoms listed are isotopes of the same
element, how can you tell?
a. 168 X
d. 178 X
f. 147 X
A and D are isotopes of the same element because they have the same atomic
number and different mass numbers
7. Given the equation: X  24 He + 230
88 Rn What particle is represented by X?
X is representing
8. Given the equation:
Pa 
e + X
What particle is represented by X?
X is representing 234
92 U
9. What is the formula mass of W(SO4)2? 376 g/mol
10. Determine the number of moles present in 100g of AlCl3.
there are 0.75 moles in 100g of AlCl3
11. What is the total number of sodium atoms in 10g of sodium? there are 2.6x1023
atoms in 10 g of sodium
12. How many molecules of CO are in 8 liters of CO? there are 2.2x1023molecules in
8L of CO
13. What is the mass of 2.3x1024 molecules of KCl? the mass is 223g
14. Calculate the number of molecules in 50.0 grams of H2SO4 3.1x1023 molecules
15. What is the name of Group 17 elements? Group 18? Group 1? Group 2
Group 17 is known as the halogens, group 18 the noble gases, group 1 the
alkali metals and group 2 the alkaline earth metals
16. What is the identity of an atom has the electron configuration 1s22s22p63s23p4.?
17. What is the total number of valence electrons of an atom of iodine in the ground
state? there are 7 valence electrons in an atom of iodine
18. Draw the Lewis dot structure of arsenic? draw As surrounded by 5 dots (there
should only be 1 pair)
19. How many valence electrons are in an atom with the following configuration:
1s22s22p63s23p3 this atom (phosphorus) has a total of 5 valence electrons
20. What is the element with the largest atomic radius? smallest? largest = Fr,
Smallest = F
21. When an electron in the excited state drops from n=4 to n=2, what color is the
photon given off? blue light
22. How does an atom form a positive ion with a 3+ charge? anion with a 2- (two
negative) charge? a 3+ charge is the result of losing 3 electrons, a 2- charge is a
result of gaining 2 electrons
23. Write the electron configuration for a sodium cation (Na1+)? 1s22s22p6
24. What is the correct formula for the ionic compound formed between sodium and
oxygen? Na2O
25. Which atoms are most likely to form covalent bonds? What happens to their
electrons? nonmetals form covalent bonds by sharing unpaired valence electrons
26. Is the molecule NH3 polar or nonpolar? are the bonds in the molecule polar or
nonpolar? NH3 is a polar molecule with polar bonds
27. Describe how the electrons are dealt with in a nonpolar covalent bond the
electrons in nonpolar bonds are shared equally between the two atoms
28. According to VSEPR, what is the shape of the SF2 molecule? bent
29. How many electrons are shared in a double bond? four electrons are being shared
30. List the diatomic molecules: H2 N2 O2 F2 Cl2 Br2 I2
31. What do the letters in VSEPR stand for? Valence Shell Electron Pair Replusion
32. List the intermolecular forces from weak to strong London dispersion, dipoledipole, hydrogen bond
33. Write the formula for the following compounds
a. Dinitrogen tetrahydride
b. Copper (II) carbonate
c. Potassium phosphate
Sulfurous acid
iodine pentafluoride
antimony tribromide
hexaboron monosilicide
barium iodate
magnesium perchlorate
silver phosphate
cobalt(III) nitrite
mercury(I) bromide
chromium(III) oxide
chlorine dioxide
34. Name the following compounds
a. FeO
Iron (II) Oxide
b. NO2
Nitrogen monoxide
c. Co3(PO4)2
Cobalt (II) phosphate
d. HBr
hydrobromic Acid
e. HClO3
Chloric Acid
f. AuF
Gold (I) Fluoride
g. CrBr2
Chromium (II) Bromide
h. AlPO4
Aluminum Phosphate
i. KNO2
Potassium Nitrite
j. CaCO3
Calcium Carbonate
k. P4S5
Tetraphosphorus pentasulfide
l. O2
m. SeF6
Selenium Hexafluoride
n. Si2Br6
Disilicon hexabromide
35. A compound has an empirical formula of CH2 and a molecular mass of 84g.
What is its molecular formula? C6H12
36. Phentyfloroform contains 57.54% C, 3.45% H, and 39.01% F. What is its
empirical formula?
57.54gC / 12= 4.795 mol / 2.05 = 2.33 x 3 = 7
3.45gH / 1 = 3.45 mol / 2.05 = 1.68 x 3 = 5
39.01gF / 19 = 2.05 mol / 2.05 = 1 x 3 = 3
37. What is the empiricial formula for N8H6? N4H3
38. What is the percent by mass of magnesium in magnesium oxide, Mg3P2? 54%
39. Balance the reaction and identify the reaction type
a. C3H8 + O2  CO2 + H2O
1, 5, 3, 4..combustion
b. C8H18 + O2  CO2 + H2O
2, 27, 8, 18..combustion
c. NaCl + F2  NaF + Cl2
2, 1, 2, 1…single replacement
d. H2 + O2  H2O
2, 1, 2 synthesis
e. K + MgBr2  KBr + Mg
2, 1, 2, 1 single replacement
f. FeCl3 + NaOH  Fe(OH)3 + NaCl
1, 3, 1, 3 double replacement
g. Ag2O  Ag + O2
2, 4, 1 decomposition
h. S8 + O2  SO3
1, 6, 4, synthesis.