Skip to content

Course home

1.1 A simple model of the atom, symbols, relative atomic mass, electronic charge and isotopes

1.1 A simple model of the atom, symbols, relative atomic mass, electronic charge and isotopes

EasyMedium
1234567891011121314151617181920212223242526272829303132333435
Question 4
44%

This question is about atomic structure, isotopes, and the periodic table.

Gallium (Ga\text{Ga}Ga) is a metal that has more than one stable isotope.

a.

Define the term 'isotopes' in terms of subatomic particles.

[2]
b.

Table 1 shows the mass numbers and percentage abundances of the two stable isotopes found in a specific sample of gallium.

Table 1

Mass numberPercentage abundance (%)
6962
7138

Calculate the relative atomic mass (ArA_rAr​) of gallium in this sample.

Give your answer to 1 decimal place.

[2]
c.

Gallium is located in Group 3 of the modern periodic table.

Determine the number of electrons and the number of neutrons in a neutral atom of the isotope 3171Ga{}^{71}_{31}\text{Ga}3171​Ga.

[2]
d.

What is the most likely formula of a gallium(III) ion?

Select one option:

  • Ga3−\text{Ga}^{3-}Ga3−
  • Ga+\text{Ga}^{+}Ga+
  • Ga2+\text{Ga}^{2+}Ga2+
  • Ga3+\text{Ga}^{3+}Ga3+
[1]
e.

Gallium was discovered in 1875, six years after Dmitri Mendeleev published his first periodic table.

Give two reasons why the discovery of gallium helped scientists to accept Mendeleev's periodic table.

[2]
Markscheme

1.1 A simple model of the atom, symbols, relative atomic mass, electronic charge and isotopes Questions

  1. GCSE
  2. /Chemistry
  3. /1.1 A simple model of the atom, symbols, relative atomic mass, electronic charge and isotopes

41 exam-style questions on AQA GCSE Chemistry 1.1 A simple model of the atom, symbols, relative atomic mass, electronic charge and isotopes, covering 1.1.1 Atoms, elements and compounds, 1.1.2 Mixtures, 1.1.3 The development of the model of the atom (common content with physics), 1.1.4 Relative electrical charges of subatomic particles, 1.1.5 Size and mass of atoms, 1.1.6 Relative atomic mass, and 1.1.7 Electronic structure. Each one has a worked solution and a mark scheme showing where the marks go.

Question bank