2.4 Density

• Natuurkunde
• Middelbare school
• vwo
• Leerjaar 2

Today

Review substance properties + mixtures

2.4 Density

What is density

Calculating density

Complete calculation

Which isn't a substance property

1. color
2. smell
3. temperature
4. flameability

You are using a tea bag to make tea. The resulting tea is called the:

1. filtrate
2. residu
3. filter
4. pure substance

You are comparing a solution with a suspension. How can you identify the solution?

1. the solution has solid objects in it
2. the solution is see-through
3. the solution is colourless
4. you need more info to answer this question

Suspension

Opaque

You can use a filter to separate the mixture

Solution

See through

You can't use a filter to separate the mixture

Which isn't a substance property

1. conductivity
2. smell
3. mass
4. boiling point

Which is heavier: a kg of feathers or a kg of lead?

1. feathers
2. lead
3. equal
4. not enough info

Density

Amount of volume for a given amount of mass

    ρ=m/V

ρ = density (g/cm³)

m = mass (g)

V = volume (cm³ or mL)

Density question 1

An object of 2 cm³  has a mass of 5,4 g. Calculate the density

Complete calculation

Complete calculation

Use density to identify a substance

An object of 2 cm³  has a mass of 5,4 g. Density 2,7 g/cm³

What is this object made of?

(refer to page 32 of your book)

Lab

40 minutes

work in pairs

hand in worksheet by end of the lesson

SAFETY: TILT THE CYLINDER WHEN ADDING OBJECTS!

Exercises

Finish exercises: 36, 37, 39, 40, 41 & 42