(a(i))[1]
Deduce the percentage by mass of the other elements present on Earth.
(a(ii))[1]
Which non-metallic element has the highest percentage by mass on Earth?
(a(iii))[2]
Give two significant differences between the percentage by mass of the elements on Earth and in the Universe.
(b)[1]
Complete the diagram so that it shows the electron arrangement in an oxygen atom.
(c(i))[1]
Explain, in terms of electronic structure, why neon does not react.
(c(ii))[1]
State one application of argon.