Topic 3 - Particle Model of Matter

Question 1

What is the formula of density?

Answer 1

density = mass/volume

Question 2

What are the units of density?

Answer 2

kg/m³

Question 3

What are the three states of matter

Answer 3

Solid,Liquid,Gas

Question 4

Describe how you could find the volume of an irregular solid object

Answer 4

1. Use a balance to measure its mass
2. Submerge the solid in a eureka can filled with water. Use a measuring cylinder to capture the displaced water.
3. Record the volume of water. This is the volume of the object

Question 5

Briefly describe an experiment to find the density of a liquid

Answer 5

1. Place a measuring cylinder on a balance and zero the balance
2. Pour 10ml of the liquid into the measuring cylinder and record the liquid’s mass
3. Pour another 10ml into the measuring cylinder, repeating the process until the cylinder is full and recording the total volume and mass each time.
4. For each measurement use the formula (d=m/v) to find density (1ml=1cm³)
5. The mean of these values is the density of the liquid

Question 6

What led to the plum pudding model of the atom being replaced?

Answer 6

• Because of the alpha particles fired at gold foil experiment
• Most alpha particles went straight through
• Therefore atoms are made of mostly empty space
• A few alpha particles bounced back
• Therefore the atom had a concentrated mass with a charged nucleus
• This led to the plum pudding model being replaced because the plum pudding model showed mass and charge being spread throughout the atom