Unit 1: Units

Question 2

Metrics

Answer 2

Question 3

Unit Analysis Method

Answer 3

• Unit equation/ unit factor
• Ratio of two units – exact number (usually)
• Unit like variable – cancelled/multiplied
  
  • 2X • 3Y/X • 2Z/3Y = 4Z
• Convert 200. g to cg
• Convert 1,200,000 m to dam

Question 4

Conversions with Exponents

Answer 4

• Can have exponential units
• Unit factor from base
• Convert 1.5 m2 to cm2

Question 5

Convert the following measurements:

• 689.2 km to cm
• 7.02x105 nL to daL
• 0.000387 g to μg

Question 6

Volume

How to measure volume? (2 ways)

Answer 6

• Volume – amount of space a body occupies
  
  • litre – L
  • mL or cm3
• Measure by calculation or displacement:
  
  • Calculation: l x w x h
    
    • Ex: 12 cm x 13 cm x 5 cm = 780 cm3
  • Displacement: difference from immersion
    
    • 37.5 mL end, 12.8 mL start:
    • 37.5 mL – 12.8 mL = 24.7 mL

Question 7

Density

Answer 7

amount of space a given mass occupies

m/V;

unit: g/cm³ or g/mL
ex: density of 2.00 cm³ sample w/ mass 5.40g?

Question 8

Specific gravity

Answer 8

= density of object (g/mL) / density of water (g/mL)

Question 9

An object with a mass of 387.989 cg is immersed in water; the volume of the water rose from 12.908 mL to 39.09 mL; what is the object’s density in g/mL? What is the specific gravity?