Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
The periodic table
20 practice questions
Practice questions
1–3 of 3 · Hard
Question 1
2 marks · Hard
Answer and see the solution →A neutral atom of silver has an atomic number of 47 and a mass number of 108. Calculate the number of electrons and neutrons in this atom.
Question 2
5 marks · Hard
Answer and see the solution →Molybdenum (Mo) is an element with an atomic number of 42. One isotope of molybdenum has a mass number of 98.
(a)[1 mark]State the number of protons in an atom of this isotope.
(b)[2 marks]Calculate the number of neutrons in this isotope.
(c)[2 marks]Explain how you would determine the number of electrons in a neutral atom of molybdenum.
Question 3
2 marks · Hard
Answer and see the solution →The symbol for antimony is Sb. An atom of antimony has 51 protons and a mass number of 123. State the number of electrons and calculate the number of neutrons in a neutral atom of antimony.