Chem 121
Homework 1
Due 9/30/2008
1. Solve the following conversions. How many significant figures are there in each
answer?
How many kilograms (kg) are in 2,050 grams (g)?
How many micrograms (ug) are in 15.5 grams?
How many cm are in 0.056 meters?
How many seconds are in 6 X 1012 milliseconds?
How many liters (L) are in 200 microliters (ul)?
2. Fill in the table below. Write the symbol, the atomic number, the mass number, the
number of protons, neutrons, and electrons for each element shown. Also classify each
as a metal, a nonmetal or a metalloid. Hydrogen is done as an example
Element
Symbol Atomic Mass
#
#
#
Metal,
Number Number protons neutrons electrons nonmetal, or
metalloid?
Hydrogen H
1
1
1
0
1
Nonmetal
Carbon
12
Silver
61
Arsenic
42
Krypton
83
3. Given that the weighted average Atomic Mass for lithium is 6.941 amu (from Table
2.9 on page 70 of the textbook), what are the relative abundances of 6Li and 7Li?
4. Identify the following as an element, a compound, a heterogeneous mixture, or a
homogenous mixture:
Gold
Grande Nonfat Mocha
Diamond
Air
Table salt, NaCl
A bucket of water I take from Puget Sound
DNA