Density

Question 1

Define the term ‘density’

Answer 1

Density is a substance’s mass per unit volume

Question 2

Write the equation that links density, mass and volume in words

Answer 2

Density = Mass/Volume

Question 3

State the symbol equation for density

Answer 3

ρ = m/V

Question 4

What are the units for:
Density:
Mass:
Volume:

Answer 4

Density: g/cm^3 kg/m^3
Mass: g or kg
Volume: cm^3 or m^3

kg/m^3 is the main unit

Question 5

What is the density of water in g/cm^3 and kg/m^3

Answer 5

Density of water = 1g/cm^3 / 1000 kg/m^3

Question 6

What is
1g/cm^3 in kg/m^3
1ml in cm^3
1m^3 in cm^3

Answer 6

1g/cm^3 = 1000kg/m^3
1ml = 1cm^3
1m^3 = 1,000,000cm^3

conversions

1g/cm^3 to kg/m^3
x1000

1ml to cm^3
x1

1m^3 to cm^3
x100^3

Question 7

Describe the method for measuring the density of a regular object

Answer 7

1) Measure the object’s mass by using a digital balance

2) Measure it’s dimensions using a ruler or a Vernier calliper, and then calculate the object’s volume

3) Using the equation, ρ=m/V, calculate the density of the object

Question 8

Describe the method for measuring the density of an irregular object using a Eureka can

Answer 8

1) Measure the object’s mass using a digit balance

2) Place the object into the Eureka can

3) The volume of the object is equal to the volume of water displaced into the measuring cylinder

4) Using the equation, ρ=m/V, calculate the density of the object

Question 9

Describe the method for measuring the density of an irregular object using a measuring cylinder

Answer 9

1) Measure the object’s mass using a digit balance.

2) Partially fill a measuring cylinder with water and record it’s volume

3) Lower the object into the measuring cylinder and record the new volume

4) The volume of the object is equal to the volume of the water displaced.

5) Using the equation, ρ=m/V, calculate the density of the object

Question 10

Describe the method for measuring the density of a liquid

Answer 10

1) Measure the mass of an empty beaker using a digital balance

2) Remove the beaker from the balance and pour a known volume of the liquid from the measuring cylinder into the beaker

3) Measure the total mass of the beaker and the liquid using a digital balance

3) Calculate the mass of the liquid by subtracting the mass of the empty beaker from the total mass of the beaker and the liquid

4) Using the equation, ρ=m/V, calculate the density of the liquid

Question 11

Fill in the gaps

Metals have ____ densities. Everything else has _____ densities

Answer 11

Metals have high densities. Everything else has low densities

Question 12

Fill in the gaps

Density is _______ proportional to volume

Answer 12

Density is inversely proportional to volume

Question 13

What are the densities of objects that can float in water

Answer 13

Objects that have a lower density than water (<1000kg/m^3) float in water

Question 14

Explain why solids have a very high density

Answer 14

The particles in a solid a packed closely together, solids have a lot of mass for their volume

Question 15

Explain why liquids have a high density

Answer 15

The particles in a liquid are close together, liquids have a lot of mass for their volume

Question 16

Explain why liquids have a low density

Answer 16

The particles in a gas are very far apart so gases only have a small mass for their volume

Question 17

Explain why polystyrene has a low density despite being a solid

Answer 17

The reason why polystyrene has a low density despite being a solid is because polystyrene has a very open structure and it is full of air spaces. It has a small mass for its volume