Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Atomic Structure
108 practice questions
Topics covered
Practice questions
11–20 of 48 · Normal
Question 11
4 marks · Normal
Answer and see the solution →Use the periodic table and your knowledge to answer the following questions about atomic numbers and mass numbers.
(a)[1 mark]Define mass number.
(b)[3 marks]An atom of element X has atomic number 9 and mass number 19.
State how many protons, neutrons and electrons are present in a neutral atom of X.
Question 12
3 marks · Normal
Answer and see the solution →An atom of magnesium has atomic number 12 and mass number 25.
Calculate the number of neutrons in this atom. Show your working.
Question 13
3 marks · Normal
Answer and see the solution →Explain the difference between the atomic number and the mass number of an atom. Give an example of each.
Question 14
4 marks · Normal
Answer and see the solution →The table below shows information about three atoms.
Properties of three atoms Atom Atomic number Mass number A 6 14 B 8 16 C 11 23 (a)[2 marks]For atom A, state the number of protons, neutrons and electrons (assuming atom A is neutral).
(b)[2 marks]Which atom in the table has the greatest number of neutrons? Show your reasoning.
Question 15
1 mark · Normal
Answer and check →Which statement about isotopes is correct?
- A.Isotopes have different numbers of protons but the same number of neutrons.
- B.Isotopes have the same number of protons but different numbers of neutrons.
- C.Isotopes have different atomic numbers but the same mass number.
- D.Isotopes have different numbers of electrons only.
Question 16
2 marks · Normal
Answer and see the solution →Name the three types of sub-atomic particles in an atom and state where each is located.
Question 17
4 marks · Normal
Answer and see the solution →An atom of lithium has atomic number 3 and mass number 7.
(a)[1 mark]State what the atomic number tells you about the atom.
(b)[2 marks]Explain how to calculate the number of neutrons in this atom and give the answer.
(c)[1 mark]Lithium has isotopes. Define 'isotope'.
Question 18
2 marks · Normal
Answer and see the solution →State the number of protons and the number of neutrons in an atom of magnesium-25 ().
Question 19
4 marks · Normal
Answer and see the solution →Use the information below to answer the questions about isotopes.
(a)[1 mark]Give the definition of isotopes.
(b)[2 marks]State one similarity and one difference between the isotopes and .
(c)[1 mark]Explain why the chemical properties of the two isotopes are the same.
Question 20
3 marks · Normal
Answer and see the solution →Bromine consists of two isotopes: and . The percentage abundances are 51% and 49% respectively. Calculate the relative atomic mass of bromine. Give your answer to 1 decimal place.