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
251–260 of 991
Question 251
1 mark · Easy
Answer and see the solution →State the number of protons in a sodium atom.
Question 252
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 253
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 254
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 255
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 256
1 mark · Easy
Answer and see the solution →What is the number of electrons in a neutral atom of chlorine?
Question 257
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 258
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.
Question 259
2 marks · Normal
Answer and see the solution →A phosphorus atom has a mass number of 31 and an atomic number of 15. State the number of protons and electrons in this atom.
Question 260
4 marks · Normal
Answer and see the solution →The symbol for silver in the periodic table shows:
Use this information to answer the following questions about a silver atom.
(a)[1 mark]State the mass number of this silver atom.
(b)[1 mark]State the atomic number of this silver atom.
(c)[1 mark]Calculate the number of neutrons in this atom.
(d)[1 mark]State the number of electrons in a neutral atom of silver.