Describe the Greek model of the atom in eight words.

Democritus originally came up with which model of the atom?

John Dalton agreed with the Greek model but theorised that each element had:
(the same/a different) atom.

Who was credited with discovering electrons?

What model of the atom did J J Thompson theorise?

Who came up with the first nuclear model?

What experiment did Rutherford use to discover the first nuclear model?

What results were expected from the alpha scattering experiment and why were they expected?

How does the prediction of the alpha scattering experiment compare to the results?

What did the results of the alpha scattering experiment prove?

Niels Bohr suggested that orbiting electrons do so at different distances called what?

James Chadwick proved the existence of which sub atomic particle and what did it help to explain?

The nucleus contains which two sub atomic particles?

What charges does each sub atomic particle in a nucleus have and what is the overall charge of a nucleus?

The radius of the nucleus is about (100/1,000/10,000) times smaller than the radius of the whole atom.

Most of an atom is comprised of mostly what?

What sub atomic particles orbit the nucleus and what charge do they have?

The number of protons is equal to the number of what? Why is this?

What are isotopes?

All isotopes have the same number of which sub atomic particle?

The number of protons defines the atomic _____ of an element.

The mass number of an atom is the sum of the total of which sub atomic particles?

Isotopes have differing numbers of which sub atomic particle?

How many elements have isotopes?

What happens to the unstable isotopes and why do they do this?

What is radioactive decay and why does it happen?

What are the three main types of radiation?

Alpha particles are what type of nuclei and why is this?

How penetrating is alpha radiation?

How far does alpha radiation travel?

What is alpha radiation stopped by?

How ionising are they?

Put the types of radiation in terms of ionisation. Starting with the highest.

Put the types of radiation in order of distance travelled. Starting with the highest.

What is beta radiation?

What is gamma radiation?

Nuclear equations show radioactive _____ by using element symbols.

How are nuclear equations written?

What is the golden rule when writing nuclear equations?

Alpha decay __________ the charge and mass of the nucleus.

Why does the mass and charge decrease when alpha decay occurs?

When alpha decay occurs, how much is the atomic number and mass number reduced by?

Why is the charge reduced during alpha decay?

Uranium 238 becomes Thorium 234 during alpha decay. Write a nuclear equation to show this.

Beta decay increases the _____ of the nucleus.

Why does beta decay increase the charge of a nucleus?

Does the mass or charge change during gamma decay? Why or why not?

Radioactivity is a (controlled/random) process.

What is half life?

What is half life measured in?

The radioactivity of a source _________ over time.

When does the activity of a radioactive source reach zero?

The initial activity of a sample is 640Bq. Calculate the final activity as a percentage of the initial activity after 2 half lives.

How can you measure the half life using a graph?