Science Yr2 Lesson 8

• Science
• Middelbare school
• havo, vwo
• Leerjaar 2

Science Year 2 lesson 8

Today

• 1.3: density

      - preparing for test 1.1-1.3 (2rd of October)

Learning Goals

I can…

• Explain the concept of density
• Calculate the density of a substance using the density formula.
  
• Use density to determine the mass or volume of a substance
• Use density to identify an unknown substance

Key Words

• Mass
• Volume
• Density

Density

Density = a measure how much matter is packed into a given area. It is a property of a substance.

The closer the molecules are, the greater the density.

Density tells us how many grams of matter there are per a unit of volume.

What is the formula for density?

Density calculations

Common units:

• grams per cubic centimeter (g/cm3) 
• grams per milliliter (g/mL)

What is the density of polonium in grams per cubic centimeter if a 0.277 g sample has a volume of 0.0297 cm3 (rounding to 2 digits)?

Density calculations

m = 0,277 g

V = 0,0297 cm³

^{ρ = m/V = 0,277 / 0,0297 = 9,33 g/cm3}

What is the density of stainless steel in grams per cubic centimeter if a 2.92 g sample has a volume of 0.390 cm3 (rounding to 2 digits)?

Density calculations

m = 2,92 g

V = 0,390 cm³

^{ρ = m/V = 2,92 / 0,390 = 7,49 g/cm3}

Density calculations

What is the volume of lead in cubic centimeters of a 84,3 g sample if its density is 11.3 g/cm3 (rounding to 2 digits)?

Density calculations

m = 84,3 g

^{ρ = 11,3 g/cm3}

^{V = m/ρ = 84,3 / 11.3 = 7,46 cm3}

What is the mass of yellow brass in grams of a 0.146 cm3 sample if its density is 8.47 g/cm3 (rounding to 2 digits)?

Density calculations

V = 0,146 cm³

^{ρ = 8,47 g/cm3}

^{m = ρ x V = 8,47 x 0.146 = 1,24 g}

What is the volume of lead in cubic centimeters of a 84,3 g sample if its density is 11.3 g/cm3 (rounding to 2 digits)?

Homework for next time

• Complete the exercises of section 1.3  
  
• Study the glossary of Topic 1.1 - 1.3 on StudyGo.