(a(i))[1]
Which element makes up 78% of the air?
(a(ii))[1]
Which element has an oxide that is a product of respiration?
(a(iii))[1]
Which element is used to make food containers because it resists corrosion?
(a(iv))[1]
Which element gives an ion of type $X^{3+}$?
(a(v))[1]
Which element forms an ion whose aqueous solution gives a light blue precipitate when a few drops of aqueous ammonia are added?
(b(i))[1]
What does the term element mean?
(b(ii))[3]
Fill in the table to show how many protons, neutrons and electrons are present in one atom of each isotope.
(b(iii))[1]
Find how many electrons are present in one calcium ion, $\text{Ca}^{2+}$.