TEST ONE
Test for week one, covers atomic structure, matter and measurement.
Matter and Measurement
1) The number of significant figures in 0.03200 is:
2) The number of significant figures in 0.0140 is:
3) In the metric system the prefix mili means:
4) In the metric system the prefix mega means:
5) Express 535.6 in scientific notation:
6) 16oF equals how many degrees Celsius?
7) What is the SI unit of length?
8) Is dissolving salt into water a physical or a chemical change?
9) Is combustion of coal a physical or a chemical change?
10) What is matter?
11) Classify the following as an element, compound or mixture:
a) Lead
b) Salted popcorn
c) Water
d) Coffee with cream
12) Write either the symbol or the name for the following elements:
a) Be
b) Potassium
c) B
d) Silver
13) Explain the law of conservation of mass:
14) How would one separate water from a salt water mixture?
15) Write true or false for the following:
a) Most elements listed in the periodic table are solids
b) Nonmetals are malleable
c) A physical change does not involve a change in the composition of the compound
d) Most elements on the periodic table are metals
16) Perform the following conversion factors:
a) 3.85 lbs. to kg given that 1 kg = 2.205 lbs.
b) 4.045 meters to kilometers
17) The density of benzene is 0.880 g/ml at 20oC. What is the mass of 1.050 liters of benzene?
Atomic structure
18) What are the number of protons, neutrons and electrons present in the following species?
a) 178O
b) 19980Hg
c) 20080Hg
ANSWERS
1) 4
2) 3
3) 10^-3
4) 10^6
5) 5.356 x 10^2
6) -8.88 degree Celsius
7) meter
8) physical
9) chemical
10) Matter can be defined as anything that occupies space.
11) a) element b) mixture c) compound d) mixture
12) a) Beryllium b) K c) Boron d) Ag
13) Matter cannot be created or destroyed only transformed from one form or another. As it relates to chemistry: the mass or quantity of matter remains constant during a chemical change
14) Distillation, you heat the water to point of boiling and collect vapor, condense it back to its liquid state and leave the salt behind.
15) a) true:
http://www.calculatoredge.com/optical%20engg/chemical%20peroidic%20table.htm
b) false, nonmetals are very brittle, and metals are malleable
c) true, chemical changes involve changes in chemical composition
d) true, metals are the majority
16) a) 3.85 lbs. (1 kg/2.205 lbs.) = 1.75 kg b) 4.045 m (1 km/1000 m) = 0.004045 km
17) Density = mass/volume, Mass = density*volume = (0.880 g/ml)(1050ml) = 924 grams
18) Recall the superscript denotes mass number and the subscript denotes atomic number. Mass number is always greater than atomic number.
a) 178O — 8 protons and electrons, (17-8) = 9 neutrons
b) 19980Hg — 80 protons and electrons, (199-80) = 119 neutrons
c) 20080Hg — 80 protons and electrons, (200-80) = 120 neutrons (species b and c are chemically similar isotopes of mercury).