Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Principles of Chemistry
991 practice questions
Topics covered
- States of Matter102 practice questions
- Elements, Compounds and Mixtures69 practice questions
- Atomic Structure108 practice questions
- The Periodic Table103 practice questions
- Chemical Formulae, Equations and Calculations Part 119 practice questions
- Chemical Formulae, Equations and Calculations Part 2144 practice questions
- Ionic Bonding143 practice questions
- Covalent Bonding68 practice questions
- Metallic Bonding19 practice questions
- Electrolysis198 practice questions
Practice questions
101–110 of 407 · Easy
Question 101
3 marks · Easy
Answer and see the solution →(a)[1 mark]Complete the following sentence: An atom is neutral because...
(b)[1 mark]Potassium has atomic number 19. State the number of electrons in a neutral atom of potassium.
(c)[1 mark]Explain your answer to part (b).
Question 102
2 marks · Easy
Answer and see the solution →Show how you would calculate the number of electrons in a neutral atom of argon, given its atomic number is 18.
Question 103
1 mark · Easy
Answer and see the solution →State the number of protons in a sodium atom.
Question 104
3 marks · Easy
Answer and see the solution →(a)[1 mark]State the number of electrons in a potassium atom.
(b)[1 mark]State the number of neutrons in a potassium-39 atom.
(c)[1 mark]State the number of protons in a potassium atom.
Question 105
2 marks · Easy
Answer and see the solution →An atom of aluminium has a mass number of 27 and an atomic number of 13.
Calculate the number of neutrons in an aluminium atom.
Question 106
2 marks · Easy
Answer and see the solution →Explain why the number of electrons in an atom must always equal the number of protons.
Question 107
3 marks · Easy
Answer and see the solution →The table below shows information for three elements:
Element Symbol Atomic number Mass number Boron B 5 11 Silicon Si 14 28 Argon Ar 18 40 Complete the following table by giving the number of protons, neutrons and electrons for each atom.
Question 108
1 mark · Easy
Answer and see the solution →What is the number of electrons in a neutral atom of chlorine?
Question 109
3 marks · Easy
Answer and see the solution →(a)[1 mark]State the number of protons in an atom of magnesium-24.
(b)[1 mark]State the number of electrons in an atom of magnesium-24.
(c)[1 mark]Calculate the number of neutrons in magnesium-24.
Question 110
2 marks · Easy
Answer and see the solution →Give the number of neutrons in a bromine atom with mass number 79 and atomic number 35.