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CHE 105/110 Introduction to Chemistry - Exercises and Answers

Expressing Numbers

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QUESTION ANSWER

1.

Express these numbers in scientific notation.

  1. 56.9
  2. 563,100
  3. 0.0804
  4. 0.00000667
 1.
  1. 5.69 × 101
  2. 5.631 × 105
  3. 8.04 × 10−2
  4. 6.67 × 10−6

3.

Express these numbers in scientific notation.

  1. 0.00656
  2. 65,600
  3. 4,567,000
  4. 0.000005507
 3.
  1. 6.56 × 10−3
  2. 6.56 × 104
  3. 4.567 × 106
  4. 5.507 × 10−6

5.

Express these numbers in standard notation.

  1. 1.381 × 105
  2. 5.22 × 10−7
  3. 9.998 × 104
 5.
  1. 138,100
  2. 0.000000522
  3. 99,980

7.

Express these numbers in standard notation.

  1. 8.09 × 100
  2. 3.088 × 10−5
  3. −4.239 × 102
 7.
  1. 8.09
  2. 0.00003088
  3. −423.9

9.

These numbers are not written in proper scientific notation. Rewrite them so that they are in proper scientific notation.

  1. 72.44 × 103
  2. 9,943 × 10−5
  3. 588,399 × 102
 9.
  1. 7.244 × 104
  2. 9.943 × 10−2
  3. 5.88399 × 107

11.

These numbers are not written in proper scientific notation. Rewrite them so that they are in proper scientific notation.

  1. 345.1 × 102
  2. 0.234 × 10−3
  3. 1,800 × 10−2
 11.
  1. 3.451 × 104
  2. 2.34 × 10−4
  3. 1.8 × 101

13.

Write these numbers in scientific notation by counting the number of places the decimal point is moved.

  1. 123,456.78
  2. 98,490
  3. 0.000000445
 13.
  1. 1.2345678 × 105
  2. 9.849 × 104
  3. 4.45 × 10−7

15.

Use your calculator to evaluate these expressions. Express the final answer in proper scientific notation.

  1. 456 × (7.4 × 108) = ?
  2. (3.02 × 105) ÷ (9.04 × 1015) = ?
  3. 0.0044 × 0.000833 = ?
 15.
  1. 3.3744 × 1011
  2. 3.3407 × 10−11
  3. 3.665 × 10−6

17.

Use your calculator to evaluate these expressions. Express the final answer in proper scientific notation.

  1. 45 × 132 ÷ 882 = ?
  2. [(6.37 × 104) × (8.44 × 10−4)] ÷ (3.2209 × 1015) = ?
 17.
  1. 6.7346 × 100
  2. 1.6691 × 10−14

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