(a(i))[1]
State the symbol for the element that makes up 78% of clean, dry air.
(a(ii))[1]
State the symbol of the element that forms an ion with a charge of 3+.
(a(iii))[1]
State the symbol of the element whose atom has only five occupied electron shells.
(a(iv))[1]
State the symbol of the element whose ion produces a light green colour in a flame test.
(a(v))[1]
State the symbol of the element used for food containers because it resists corrosion.
(a(vi))[1]
State the symbol of the metal with the lowest reactivity.
(b(i))[1]
Helium is a monatomic gas. State what monatomic means.
(b(ii))[1]
Helium is a monatomic gas. Explain why helium is unreactive, using its electronic configuration.