AS AQA Phys Unit 1 (1)

Created by: Jessica Parkes
Created on: 26-03-13 20:52

Describe the nuclear model of the atom (3 marks)

Inside every atom there is a nucleus which contains protons and neutrons. (1) Orbiting this central nucleus is the electrons. (1) The tiny electrons orbit at comparitavely vast distances, so most of the atom is empty space. (1)

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How many protons, neutrons and electrons are there in a neutral atom of Oxygen that has an atomic number of 8 and mass number of 16? (2 marks)

The atomic number is 8 so there must be 8 protons and 8 electrons. (1) The mass number is the total number of protons and neutrons. Subtract 8 protons from 16 and that leaves 8 neutrons. (1)

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Define the term 'isotope' and describe the similarities and differences between the properties of two isotopes of the same element. (3 marks)

Isotopes are atoms with the same number of protons but different number of neutrons. (1) Two isotopes of the same element have the same chemical properties (1) but different physical properties (1)

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Explain why the strong nuclear force must be repulsive at short distances. (1 mark)

The strong nuclear force must be repulsive at very small nucleon seperations to prevent the nucleus being crushed to a point. (1)

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How does the strong interaction due to the strong nuclear force limit the size of a stable nucleus? (2 marks)

Beyond a few fm the strong nuclear force is smaller than the electrostatic force. (1) This means the protons in the nucleus would be forced apart. So a bigger nucleus than this would be unstable (1)

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What happens when an alpha particle is emitted? (2 marks)

Atomic number decreases by two (1) Mass number decreases by four (1)

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What happens when a beta-minus particle is emitted? (4 marks)

The beta-minus particle is an electron. (1) Atomic number increases by one (1) Mass number stays the same (1) an anti-neutrino is released (1)

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Where does beta decay happen? (1 mark)

In isotopes that have more neutrons than protons in their nucleus. (1)

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Other cards in this set

Card 2

Front

How many protons, neutrons and electrons are there in a neutral atom of Oxygen that has an atomic number of 8 and mass number of 16? (2 marks)

Back

The atomic number is 8 so there must be 8 protons and 8 electrons. (1) The mass number is the total number of protons and neutrons. Subtract 8 protons from 16 and that leaves 8 neutrons. (1)

Card 3

Front

Define the term 'isotope' and describe the similarities and differences between the properties of two isotopes of the same element. (3 marks)

Back

Card 4

Front

Explain why the strong nuclear force must be repulsive at short distances. (1 mark)

Back

Card 5

Front

How does the strong interaction due to the strong nuclear force limit the size of a stable nucleus? (2 marks)

Back

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AS AQA Phys Unit 1 (1)