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 423 · Normal
Question 101
4 marks · Normal
Answer and see the solution →The following information is given about three atoms:
Data about three atoms Atom Atomic number A 6 B 18 C 2 (a)[1 mark]State the number of electrons in atom A.
(b)[1 mark]State the number of electrons in atom B.
(c)[1 mark]State the number of electrons in atom C.
(d)[1 mark]Explain why the number of protons is equal to the number of electrons in a neutral atom.
Question 102
3 marks · Normal
Answer and see the solution →Potassium is a metal with an atomic number of 19.
Calculate the number of electrons in a neutral atom of potassium. Show your working.
Question 103
4 marks · Normal
Answer and see the solution →The table shows the atomic numbers of four elements.
Atomic numbers of elements Element Atomic number Fluorine 9 Neon 10 Sodium 11 Aluminium 13 (a)[1 mark]Which element in the table has 13 electrons in its atom? Give its name.
(b)[1 mark]Which of these elements has 9 electrons in its atom? Give its name.
(c)[2 marks]Explain why the number of electrons in a neutral atom is the same as its atomic number.
Question 104
1 mark · Normal
Answer and check →Which statement is correct for a neutral atom of sulfur (atomic number 16)?
- A.It has 8 electrons.
- B.It has 16 electrons.
- C.It has 32 electrons.
- D.It has 16 protons and 8 electrons.
Question 105
2 marks · Normal
Answer and see the solution →Give the number of electrons in each of the following neutral atoms:
(a)[1 mark]Chlorine (atomic number = 17)
(b)[1 mark]Argon (atomic number = 18)
Question 106
4 marks · Normal
Answer and see the solution →The table below lists the names and atomic numbers of four different elements.
Elements and their atomic numbers Element Atomic number Carbon 6 Oxygen 8 Sodium 11 Chlorine 17 (a)[1 mark]Write down the number of electrons in a neutral atom of oxygen.
(b)[1 mark]Write down the number of electrons in a neutral atom of sodium.
(c)[1 mark]Write down the number of electrons in a neutral atom of chlorine.
(d)[1 mark]Explain why the number of electrons is the same as the atomic number in a neutral atom.
Question 107
2 marks · Normal
Answer and see the solution →State the number of electrons in a neutral atom of fluorine, which has an atomic number of 9. Give your answer with a reason.
Question 108
4 marks · Normal
Answer and see the solution →A student is studying atoms of three elements: Element X, Element Y, and Element Z.
Atomic numbers of three elements. Element Atomic number X 5 Y 12 Z 8 (a)[1 mark]State the number of electrons in a neutral atom of element X.
(b)[2 marks]Explain why the number of electrons in a neutral atom of element Y is 12.
(c)[1 mark]Calculate the total number of electrons in 2 neutral atoms of element Z.
Question 109
3 marks · Normal
Answer and see the solution →Calculate the number of electrons in a sample containing 5 neutral atoms of beryllium. Atomic number of beryllium = 4. Show your working.
Question 110
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.