Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Counting the number of electrons in an atom
21 practice questions
Practice questions
1–3 of 3 · Hard
Question 1
2 marks · Hard
Answer and see the solution →Sulfur has an atomic number of 16.
Calculate the number of electrons in two neutral atoms of sulfur.
Question 2
5 marks · Hard
Answer and see the solution →The table below gives information about three elements.
Atomic number of elements Element Atomic number A 7 B 12 C 15 (a)[1 mark]State the number of electrons in a neutral atom of element B.
(b)[2 marks]Element C is found in a rock sample containing 5 atoms. Calculate the total number of electrons in all these atoms.
(c)[2 marks]Explain why a neutral atom of element A contains the same number of electrons as its atomic number.
Question 3
2 marks · Hard
Answer and see the solution →Cobalt has an atomic number of 27.
Give the number of electrons in a neutral atom of cobalt and explain your answer.