Name the positive ion in Table 2.1 that has the smallest concentration in blood plasma.
Name the ion in Table 2.1 that contains an element from Group V of the Periodic Table.
Name the compound formed from $\text{Na}^+$ ions and $\text{SO}_4^{2-}$ ions.
Describe a test for chloride ions. State the test and the observations made.
Choose from the list the salt that does not dissolve in water. Tick ($\checkmark$) one box. calcium sulfate magnesium chloride potassium sulfate sodium chloride
Use the information in Table 2.2 to explain why it is hard to predict the density of rubidium and to describe what is seen when sodium reacts with water.
State how the melting point of the Group I elements varies down the Group.
Sodium oxide, $\text{Na}_2\text{O}$, may be prepared by heating sodium in a restricted supply of oxygen. Complete the symbol equation for this reaction: $\ldots\text{Na} + \text{O}_2 \rightarrow \ldots\text{Na}_2\text{O}$.