1. Semester I Review
ANSWERS

2. Semester I Review How many sig-figs are found in each number? 0.345 3
300 1

3. Semester I Review Round each number to three sig-figs. 45678 45700

4. Semester I Review Which of the following is a mixture.
Pure water compound
Clean air homogenous mixture
Iron (II) oxide compound
Salt water homogenous mixture
Carbon dioxide compound

5. Semester I Review Which of the following is a chemical change.
Cutting paper physical
Boiling water physical
Rusting iron chemical
Burning gasoline chemical

6. Complete the table using the given numbers
Symbol
Mass #
Atomic #
Protons
Neutrons
Electrons
X - _25__ 25 10 15
Y - 35 35 14 21
Z - _56__ 56 31

7. Semester I Review
Calculate the average atomic mass given the following data: element Y has three isotopes 35.0% = 23.5 amu, 55.0% = 25.0 amu and 10.0% = 26.0 amu.
(35x23.5) + (55x25.0) + (10x26.0) = 24.6
100

8. Semester I Review
25.0 grams of a given metal displaces 44.2 mL of water; what is the density of the metal?
25.0g/44.2mL = 0.566g/mL

9. Semester I Review
What did each scientist contribute to the development of the modern atom.
Dalton = proof of the atom
Thomson = cathode rays are electrons
Rutherford = dense positive nucleus, electrons outside nucleus, atom mostly empty space
Milliken = mass to charge ratio of the electron

10. Determine if the data below is accurate, precise, both, or neither
Trial #
Measurement
True Value = 34.50 1
34.56
Accurate and precise 2
34.45 3
34.78
Calculate the percent error using the average of the measurements.
(34.60 – 34.50) x = %
34.50

11. Semester I Review
The splitting of a nucleus is known as ___fission _____.
The combining of two small nuclei to form a larger one is known as ____Fusion______.
Give the formula of an alpha particle and beta particle.

12. Semester I Review Decay of polonium-218 by alpha () emission.
Decay of carbon – 14 by beta emission 
Decay of Thorium by an electron capture 

13. Semester I Review
The half-life of phosphorous-30 is 2.5 min. If you start with 55 g of phosphorus-30, how many grams would remain after 27.5 min?
Mfinal = (55g)(.5)11 = 0.027g

14. Semester I Review
Calculate the specific heat of an unknown metal, given that 25.0g of the metal lost 3570 J of energy during a temperature change from 100.0oC to 25.0oC
c = 3570J / (25.0g)x(75.0oC)
c = 1.90 J/goC

15. Semester I Review
Identify each of the letters on the graph and explain what is occurring.
C = solid warming/cooling
D = Phase change solid to liquid or vice versa
E = liquid warming/cooling
F = phase change liquid to gas or vice versa
G = gas warming/cooling C D E F G

16. Semester I Review
Label the solid, liquid, and gas regions on the graph.
Label the triple point and critical point
At 600oC and 90 atm, what phase is yummygum in? liquid
Label the solid, liquid, and gas regions on the graph.
Label the triple point and critical point
At 600oC and 90 atm, what phase is yummygum in?
Critical point
liquid
solid
Triple point
gas

17. Semester I Review Give the formula for the following compounds
1) iron (II) arsenide Fe3As2
2) lead (II) sulfate PbSO4
3) lead (IV) hydroxide Pb(OH)4
4) copper (II) acetate Cu(C2H3O2)2
5) beryllium chloride BeCl2
6) ammonium chromate (NH4)2CrO4
7) silver oxide Ag2O
8) potassium sulfide K2S

18. Semester I Review Give the name of the following compounds
1) NaBr Sodium Bromide
2) Sc(OH)3 Scandium (III) Hydroxide
3) V2(SO4)3 Vanadium (III) Sulfate
4) NH4F Ammonium Fluoride
5) CaCO3 Calcium Carbonate
6) NiPO4 Nickel (III) Phosphate
7) Li2SO3 Lithium Sulfite
8) Zn3P2 Zinc Phosphide
9) Sr(C2H3O2)2 Strontium Acetate
10) Cu2O Copper (I) Oxide

19. Semester I Review Name the compounds H2SO3 Sulfurous Acid
H2S Hydrosulfuric acid
H3PO4 Phosphoric acid
HCN Hydrocyanic acid
H3P Hydrophosphoric acid
HBr Hydrobromic acid
HClO Hypochlorous acid

20. Semester I Review Give the formula for the following compounds
hydrofluoric acid HF
hydroselenic acid H2Se
carbonic acid H2CO3
nitrous acid HNO2
sulfuric acid H2SO4
hydrobromic acid HBr
Chlorous acid HClO2

21. Semester I Review Antimony tribromide SbBr3 Silicon difluoride SiF2
Tetracarbon octahydride C4H8
Dinitrogen monoxide N2O
Pentaphosphorous decoxide P5O10
Sulfur hexachloride SF6

22. Semester I Review P2O5 Diphosphorous pentoxide SO2 Sulfur dioxide
NO2 Nitrogen dioxide
AsCl3 Arsenic trichloride
P4H8 Tetraphosphorous octahydride

23. Semester I Review Balance and classify the reactions
_2_ C8H18 + _25_ O2  _16_ CO2 + _18_ H2O
____ FeCl3 + _3__ NaOH  ____ Fe(OH)3 + _3__NaCl
_4__ P + __5_O2  _2__P2O5
_2__ Na + _2__ H2O  __2_ NaOH + ____H2
_2__ Ag2O  _4__ Ag + ____O2
____ S8 + _12_ O2  _8__ SO3