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Answer Key

  • Page ID
    189360
  •  1) No, it is not a proper answer; you do not know whether the professor meant homework problem number 20 or 20 homework problems. Twenty is a quantity and does not make sense without a unit

    3)

    Middle Zeros: Zeros that appear between other nonzero digits are ALWAYS significant.

    Leading Zero: Zeros that appear in front of all nonzero digits are NEVER significant.

    Trailing Zero with a decimal point: Trailing zeros in a number with a decimal point are significant.

    Trailing Zero without a decimal point: Trailing zero in a number without a decimal points are ambiguous.

     

    5) A conversion factor is a fraction whose numerator and denominator. The system is set up will result in the units in numerator and denominator cancels leaving behind the desire unit.

    Scientific Notation

    7) a)1.0000 x 108 b) 4.970 x 10-4  c)3.001 x 101 d) 2.500 x 103

     9) a) 7.36350 x 105    b)3.9 x 10-3   c) 2.500 x 103 d) 4.78 x 10-1

    11) a) 86200 b) 0.0055 c) 0.00000102 d) 0.000000000603

    13) a) 4700 b) 7.410 x 103 c) 0.00093 d) 4.5 x 10-3

    15) a) 840,000 b) 5.13 x 102 c) 0.00000630 d) 2.50 x 10-1

    Significant Figures

    17) a) 6.46 cm b) 33.5 mL c) 6.28 mL

    19) a) 6 SF    all non-zeros are significant

                          all leading zeros are not significant

                          all middle zeros are significant

                          all trailing zeros with a decimal point are significant

           b) 6 SF   all non-zeros are significant

                          all middle zeros are significant

           c) 6 SF   all non-zeros are significant

                          all trailing zeros with a decimal point are significant

           d) 3 SF   all non-zeros are significant

                          all leading zeros are not significant

    21) a) 6 SF    all non-zeros are significant

                          all leading zeros are not significant

                          all middle zeros are significant

                          all trailing zeros with a decimal point are significant

           b) 6 SF   all non-zeros are significant

                          all middle zeros are significant

           c) 6 SF   all non-zeros are significant

                          all trailing zeros with a decimal point are significant

           d) 3 SF   all non-zeros are significant

                          all leading zeros are not significant

    23) a) 5 SF b) 4 SF c) 4 SF d) 4 SF

    Rounding

    25) a) 24.6 b) 0.342 c) 4.35 x 104 d) 7.00 x 103

    27) a) 5.65 x 101 b) 8.90 x 108 c) 1.00 x 106 d) 0.984

    29) a) incorrect; 4.56 x 103 b) incorrect; 8.51 x 103  c) correct d) incorrect; 0.0531

    31) b) 216.4, 2.2 x 102, 2 x 102

           c) 0.3668, 0.37, 0.4

           d) 0.008889, 0.0089, 0.009

    33) b) 654.9, 6.5 x 102, 7 x 102

          c) 0.7513, 0.75, 0.8

          d) 0.007778, 0.0078, 0.008

    Significant Figures in Calculations

    35) a) 4986.2 b) 1.1 c) correct d) 0.154

    37) a) 55 b) correct c) 0.86 d) 0.001

    39) a) 48 b) 2597 c) correct d) 0.009

    41) a) correct b) 6.220 x 103 c) 136 d) 4.5315

    Unit Conversion

    43) a) 1.000 x 106 mg b) 6.981 x 10-6 m c) 1.5 x 10-2 L d) 3.45 x 103 mm

    45) a) 3.4 x 104g b) 7.53934 x 10-6 m c) 3.6 x 103 cL d) 1.09 x 103 mm

    47) a) 4.76 x 104 mm b) 6.71 kg c) 0.248 mi d) 30.5 cm

    49)

             m

    km

    mm

    nm

          pm

    6.02 x10-5 m

    6.02 x 10-8 km

    6.02 x 10-2 mm

    6.02 x 104 nm

    6.02 x 107 pm

    2.53 x 10-11 m

    2.53 x 10-14 km

    2.53 x 10-8 mm

    0.0253 nm

    25.3 pm

    2.25 x 10-7 m

    2.25 x 10-10 km

    0.000225 mm

    225 nm

    2.25 x 105 pm

    8.22 m

    8.22 x 10-3 km

    8.22 x 103 mm

    8.22 x 109 nm

    8.22 x 1012 pm

    4.20 x 102 m

    0.42

    4.2 x 105 mm

    4.2 x 1011 nm

    4.2 x 1014 pm

     

    51)

             m

    km

    mm

    nm

          pm

    1.88 x10-5 s

    1.88 x 10-8 km

    1.88 x 10-2 mm

    1.88 x 104 nm

    1.88 x 107 pm

    1.43 x 10-11 m

    1.43 x 10-14 km

    1.43 x 10-8 mm

    0.0143 nm

    14.3 pm

    3.65 x 10-7 m

    3.65 x 10-10 km

    0.000365 mm

    365 nm

    6.65 x 106 pm

    6.34 m

    6.34 x 10-3 km

    6.34 x 103 mm

    6.34 x 109 nm

    6.34 x 109 pm

    6.9 x 102 m

    6.9 km

    6.9 x 105 mm

    6.9  x 108 nm

    6.9 x 1011 pm

     

    Unit Raised to a Power

    53) a) 3.5 x 102 in2 b) 2.2 x 101 ft2 c) 3.1 yd3

    55) a) 5.33 x 103 in2 b) 3.44 x 106 mm c) 3.44 x 10-6 km

    57) a) 2.09 x 104 in2 b) 1.35 x 107 mm2 c) 1.35 x 10-5 km

    Density

    59) 11.33 g/mL, yes

    61) a) 2.34 x 103 g b) 69.1 cm3

    63) a) 6.894 x 103 g b) 70.76 cm3

    Cumulative Problems

    65) $63.54

    67) 6.52 x 103 h

    69) 32.5 lb of apples