Unit: Scientific Measurement“One, Two, and More Step Problems” – Wksh #2 1.How many g are equal to 345.7 mg?
2.Change 0.00765 kL into mL.
3.How many seconds are there in 2.5 days?
4.How many minutes are there in 1.000 week?
5.How many seconds long is this chemistry class if it lasts 40.0 minutes?
6.A chemistry student’s height is measured at 68.5 inches. How tall is the student in cm?
7.This same chemistry student has a weight of 155 lbs. What is the student’s weight ingrams? (16oz=1lb, 1 oz = 28.34 g)
8.A homerun in a baseball game was measured at 450 feet. How many meters is this equalto?
9.Mount Everest is approximately 8,000 meters high. How many miles high is MountEverest?
10.A 5.0 km race is scheduled for this weekend. How many miles is this race?

1. 0.3457g

2. 7650mL

3. 216000 seconds

4. 10080minutes

5. 2400 seconds

6. 173.99cm

7. 70283.2g

8. 137.16metres

9. 4.968miles

10. 3.105miles

Explanation:

1. 1000mg = 1g

345.7 mg = 345.7/1000

= 0.3457g

2. 1kL = 1000000mL

0.00765 kL = 0.00765 × 1000000

= 7650mL

3. 1 day = 86400s

2.5 days = 2.5 × 86400

= 216000 seconds

4. 1 week = 10080minutes

1.000weeks is equivalent to 1 week, hence there are 10080minutes in 1.000week.

5. 1minute = 60seconds

40.0minutes = 40 × 60

= 2400seconds.

6. 1 inch = 2.54cm

68.5inches = 68.5 × 2.54

= 173.99cm

7. 1Ib = 16oz

155Ibs = 155 × 16

= 2480 oz

1 oz = 28.34 g

2480oz = 2480 × 28.34

= 70283.2g

8. 1 foot = 12 inches

450 feet = 450 × 12

= 5400inches

1 inch = 0.0254metres

5400 inches = 5400 × 0.0254

137.16metres

9. 1 metre = 0.000621 mile

8000 metres = 8000 × 0.000621

= 4.968miles

10. 1 kilometers = 1000 metres

5km = 5 × 1000

= 5000metres

1 metre = 0.000621 mile

5000metres = 5000 × 0.000621

= 3.105miles

percent abundance for cu-63 can be shown as:

63 x + 65 (1-x) = 62.9296

65 - 62.9296 = 2 x

x = 1.035

thus, percent abundance for cu-63 is 1.035

percent abundance for cu-65 can be shown as:

63 x + 65 (1-x) = 64.9278

65 - 64.9278 = 2 x

x = 0.0361

thus, percent abundance for cu-63 is 0.0361

the mass spectrum of cu-63 showing the intense peak as, this isotope is found in nature more abundantly around 92.38 % in comparison to cu-65 which is found 62.58 % naturally