NAME
7-4
DATE
PERIOD
Word Problem Practice
Scientific Notation
1. PLANETS Neptune’s mean distance from
the Sun is 4,500,000,000 kilometers.
Uranus’ mean distance from the Sun is
2,870,000,000 kilometers. Express these
distances in scientific notation.
5. COAL RESERVES The table below shows
the number of kilograms of coal select
countries had in proven reserve at the
end of a recent year.
Coal Reserves
Neptune: 4.5 × 109 km; Uranus:
2.87 × 109 km
2. PATHOLOGY The common cold is
caused by the rhinovirus, which
commonly measures 2 × 10-8 m in
diameter. The E. coli bacterium, which
causes food poisoning, commonly
measures 3 × 10-6 m in length. Express
these measurements in standard form.
Coal (kg)
United States
2.46 × 1014
Russia
1.57 × 1014
India
9.24 × 1013
Romania
4.94 × 1011
Source: British Petroleum
Rhinovirus: 0.00000002 m; E. coli:
0.000003 m
a. Express each country’s coal reserves
in standard form. United States:
246,000,000,000,000 kg;
Russia: 157,000,000,000,000 kg;
India: 92,400,000,000,000 kg;
Romania: 494,000,000,000 kg
3. COMMERCIALS A 30-second
commercial aired during the 2007 Super
Bowl cost $2,600,000. A 30-second
commercial aired during the 1967 Super
Bowl cost $40,000. Express these values
in scientific notation. How many times
more expensive was it to air an
advertisement during the 2007 Super
Bowl than the 1967 Super Bowl?
b. How many times more coal does the
United States have than Romania?
4.98 × 102 or 498 times
2007 Super Bowl: $ 2.6 × 106; 1967
Super Bowl: $ 4 × 104;
6.5 × 101 or 65 times more
expensive
c. One kilogram of coal has an energy
density of 2.4 × 107 joules. What is the
total energy density of the United
States’ coal reserve? Express your
answer in scientific notation.
4. AVOGADRO’S NUMBER Avogadro’s
number is an important concept in
chemistry. It states that the number
6.022 × 1023 is approximately equal to
the number of molecules in 12 grams of
carbon 12. Use Avogadro’s number to
determine the number of molecules in
5 × 10-7 grams of carbon 12.
5.90 × 1021 joules
2.509 × 1016 molecules
Chapter 7
27
Glencoe Algebra 1
Lesson 7-4
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
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