The Particle Model (OCR GCSE Physics A (Gateway))

The model of the atom has changed over time.

Complete the sentences using the words from the list.

You may use each word once, more than once, or not at all

i) Greek and Indian philosophers were the first to propose the idea of everything being made up of ...................................... parts.

[1]

ii) JJ Thomson discovered the ...................................... at the end of the 19th Century.

[1]

iii) JJ Thomson's Plum Pudding model consisted of negatively charged particles in a ...................................... charged dough.

[1]

iv) In 1909 Rutherford carried out his ...................................... particle experiment.

[1]

Rutherford made three discoveries from his alpha particle scattering experiment. These are shown in Fig. 1.1.

Fig. 1.1

Draw one line from each discovery to its correct diagram.

Following Rutherford's experiment, Niels Bohr proposed a modification to the model.

Complete the sentences about Bohr's model. 

Choose answers from the box. 

You can use each word once, more than once, or not at all.

 Electrons orbit the .................... at different distances.

The different orbit distances are called .................... .

The greater the distance from the nucleus, the .................... the energy.

Fig. 1.2 shows an atom according to the Bohr model.

Fig. 1.2

Label the diagram with the correct word(s) by writing them in the correct boxes.

Atomic models have changed over time.

Old atomic model – Atoms are a positive mass with negative electrons fixed in it.

Current atomic model – Atoms are made from protons, neutrons and electrons. Protons and neutrons are in a central nucleus surrounded by a cloud of electrons.

(i) Write down two differences between these models.

1 ..............................................................................................

2 ...............................................................................................

[2]

(ii) Why did the atomic model change?

[2]

A student has data on four blocks of different materials.

Each block has the same volume.

i) Plot this data onto the graph and draw a line of best fit.

[2] 

ii) Describe the pattern shown on the graph.

[2]

A student uses a ruler to determine the volume of a cube, A. The length of one side of the cube is 0.100 m.

i) Calculate the volume of cube A.

Volume of cube A = ....................................................m³ [2]

ii) Cube B has the same volume as cube A.

The mass of cube B is ten times greater than the mass of cube A.

Compare the density of cube B with cube A.

Use the equation for density to help your explanation.

[2] 

A student researches how the density of air varies with the temperature of the air. Look at the graph of her findings.

Describe the relationship between the temperature and density of air shown in the graph.

Give one reason why a solid is more dense than a gas.

Higher Tier Only

A boat can be made out of concrete.

Explain why a concrete boat floats but a lump of concrete sinks.

A piece of wood, shown below, has a density of 180 kg/m³.

Calculate the mass of this piece of wood. Show your working and give the units.

Answer: ........................... Units ..........