AQA GCSE Chemistry Year 10 Test

Which of the following statements correctly describes the structure of an atom?

• Atoms consist of protons, electrons, and neutrons all located in the nucleus.

• Protons and neutrons are located in the nucleus, while electrons orbit around the nucleus.

• Electrons and neutrons are located in the nucleus, while protons orbit around the nucleus.

• Protons and electrons are located in the nucleus, while neutrons orbit around the nucleus.

Explain the significance of the number of protons in determining the identity of an element.

What happens to an atom when it forms a positive ion?

• It gains electrons.

• It loses electrons.

• It gains protons.

• It loses neutrons.

Which statement is correct about the formation of a negative ion?

• A negative ion is formed when an atom loses electrons.
  

• A negative ion is formed when an atom gains protons.

• A negative ion is formed when an atom gains electrons.

• A negative ion is formed when an atom loses protons.

What distinguishes isotopes of the same element?

• Number of neutrons

• Number of protons

• Number of electrons

• Atomic mass

Carbon-12 and Carbon-14 are isotopes of carbon. How do these isotopes differ?

Given the relative atomic masses of isotopes A and B as 10 and 11, respectively, and their abundances as 75% and 25%, what is the relative atomic mass of the element?

• 10.25

• 10.5

• 10.75

• 11.0

Calculate the relative atomic mass of an element with two isotopes: isotope X with mass 20 and abundance 80%, and isotope Y with mass 22 and abundance 20%.

How many electrons can the second electron shell hold at most?

• 2

• 6

• 8

• 18

An atom has an electronic configuration of 2,8,8. How many electrons does this atom have in its outermost shell?

• 2

• 18

• 6
• 8