3.Express the answers to the following calculations in scientific notation: (12 points)
1.
145.75 + (2.3 × 10
–1
) 1.4598x10
2
2.
79,500 ÷ (2.5 × 10
2
)
3.18x10
2
3.
(7.0 × 10
–3
) – (8.0 × 10
–4
) 6.2x10
-3
4.
(1.0 × 10
4
) × (9.9 × 10
6
) 9.9x10
10
(Reference: Chang 1.31)
4.What is the number of significant figures in each of the following measurements? (8 points)
a.
4867 mi
4
b.
56 mL
2
c.
60,104 ton
5
d.
2900 g
2-4
e.
40.2 g/cm
3
3
f.
0.0000003 cm
1
g.
0.7 min
1
h.
4.6 × 10
19
atoms 2
(Reference: Chang 1.33
5.Express the results in the proper number of significant figures. (12 points)
1.
5.6792 m + 0.6 m + 4.33 m
10.6092m
(5)
2.
3.70 g – 2.9133 g
0.7867g (4)
3.
4.51 cm × 3.6666 cm
16.536366 cm
(8)
4.
(3 × 10
4
g
+ 6.827g)/(0.043 cm
3
– 0.021 cm
3
)
30006.827g/.022 cm
3
(Reference: Chang 1.35)
6.Carry out the following conversions: (16 points)
2.25.4 mg to kilograms .0254 kg
3.556 mL to liters .556 l
3
7.The average speed of helium at 25°C is 1255 m/s. Convert this speed to miles per hour (mph). (4 points)
8.How many minutes does it take light from the sun to reach Earth? (The distance from the
