Practise The structure of an atom. 13 exam-style questions on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
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An electron absorbs electromagnetic radiation. Describe how the position of the electron can change.
It moves further from the nucleus, to a higher energy level.
State the relative charge of a proton.
+1
Sample questions
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy2 marks
(a) Which particle has a relative charge of 0 and a relative mass of approximately 1? Tick (✓) one box.[1]
Proton
Neutron
Electron
(b) State the relative charge of a proton.[1]
Show the answer and mark scheme
(a)Answer: Neutron
(b)Answer: +1
+1 (positive)
Question 2Medium6 marks
The radius of an atom is about 1 × 10−10 m. The radius of a nucleus is less than 1/10 000 of the radius of the atom.
(a) Calculate the maximum radius of the nucleus of an atom of radius 1 × 10−10 m.[2]
(b) A teacher makes a scale model of an atom. A bead of radius 2.0 mm represents the nucleus. Calculate the minimum radius of the atom in the model. Give your answer in metres.[2]
(c) Most of the mass of an atom is concentrated in the nucleus. Explain why an atom is described as mostly empty space.[2]
Show the answer and mark scheme
(a)Answer: 1 × 10−14 m
1 × 10−10 ÷ 10 000
1 × 10−14 (m)
(b)Answer: 20 m
2.0 mm × 10 000 = 20 000 mm
20 (m)
(c)Answer: The nucleus is at least 10 000 times smaller in radius than the atom and the electrons are far away from it, so almost all of the volume of the atom contains nothing.
the nucleus is tiny compared with the atom / at least 10 000 times smaller in radius
the electrons are far from the nucleus, so most of the volume of the atom contains no particles
Question 3Hard3 marks
A human hair has a diameter of about 80 micrometres (1 micrometre = 1 × 10−6 m). A typical atom has a diameter of about 2 × 10−10 m.
Estimate how many atoms would fit side by side across the diameter of the hair. Give your answer to 1 significant figure.[3]