Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Atomic Structure
108 practice questions
Topics covered
Practice questions
41–48 of 48 · Normal
Question 41
4 marks · Normal
Answer and see the solution →(a)[1 mark]The symbol for tin is Sn. An atom of tin has atomic number 50 and mass number 120.
State the number of electrons in a neutral atom of tin.
(b)[1 mark]Calculate the number of neutrons in this tin atom.
(c)[2 marks]Explain, using numbers, why the atomic number and the number of protons in tin are always the same.
Question 42
3 marks · Normal
Answer and see the solution →An atom of zirconium has an atomic number of 40 and a mass number of 91.
Calculate the numbers of protons, neutrons, and electrons in this atom. Show your working.
Question 43
3 marks · Normal
Answer and see the solution →Explain, using an example, how you can determine both the number of electrons and the number of neutrons in an atom using information from the Periodic Table.
Question 44
4 marks · Normal
Answer and see the solution →The table shows data for four elements.
Element Symbol Atomic number Mass number Sulfur S 16 32 Iron Fe 26 56 Nickel Ni 28 59 Krypton Kr 36 84 (a)[2 marks]Use the information to complete the table below by filling in the number of neutrons for each element.
Element Number of neutrons Sulfur Iron Nickel Krypton (b)[1 mark]Which element in the table has the greatest number of protons?
(c)[1 mark]Which element in the table has the same number of protons as electrons?
Question 45
6 marks · Normal
Answer and see the solution →This question is about atoms, molecules, and the structure of the atom.
(a)State what is meant by each of the following terms:
(i)[1 mark]atom
(ii)[1 mark]molecule
(b)[3 marks]The diagram below represents a simple atom.
A simplified atom diagram showing a nucleus at (0,0) and two shells around it. Name the three types of sub-atomic particles found in atoms and state the position of each.
(c)[1 mark]The atomic number of lithium is 3, and its mass number is 7.
Calculate the number of each type of sub-atomic particle in one atom of lithium.
Question 46
6 marks · Normal
Answer and see the solution →A molecule of ammonia has the formula .
(a)[1 mark]State what is meant by the term molecule.
(b)[3 marks]Complete the table below for the sub-atomic particles in a nitrogen atom.
Properties of sub-atomic particles in a nitrogen atom Relative mass Relative charge Position in atom Proton Neutron Electron (c)Given that the atomic number of nitrogen is 7 and the mass number of its most common isotope is 14:
(i)[1 mark]Calculate the number of neutrons in a nitrogen atom.
(ii)[1 mark]Determine the total number of electrons in a molecule of ammonia ().
Question 47
6 marks · Normal
Answer and see the solution →Chlorine exists in nature as two main isotopes: and .
(a)[2 marks]Define the term isotope.
(b)[2 marks]Explain the difference between an atom and a molecule, using chlorine as an example.
(c)[2 marks]Given that the relative abundances of and are 75% and 25% respectively, calculate the relative atomic mass of chlorine. Show your working.
Question 48
6 marks · Normal
Answer and see the solution →A sample contains molecules of ammonia, .
(a)[2 marks]State the meanings of the terms 'atom' and 'molecule'.
(b)[2 marks]Each ammonia molecule contains one nitrogen atom (N) and three hydrogen atoms (H). The nitrogen atom in this molecule has a mass number of 15 and an atomic number of 7. Each hydrogen atom has a mass number of 1 and an atomic number of 1.
i. Calculate the total number of protons in one molecule of ammonia, using your answer to part (a) and the information above.
(c)[2 marks]ii. Calculate the total number of neutrons in one ammonia molecule, using the mass numbers given above.