Mark the correct statement:
(a) Sodium metal forms positive ions.
(b) Magnesium forms $M{g}^{2+}ions$.
(c) Aluminium forms negatively charged ion.

Q. Hardness to water is caused by the presence of calcium $\left(C{a}^{2+}\right)$ and magnesium $\left(M{g}^{2+}\right)$ ions. Which are the least soluble forms of calcium and magnesium at normal water temperature ?

Q. How do negative and positive ions form?

Q. Why Metals form positive ions?

Q. Complete the incomplete statements with missing words:
(a) Metals are _________ while non-metals are ___________ poor conductors of heat.
(b) Metals are malleable while non-metals are ___________.
(c) Metals form positive ions while non-metals ___________.
(d) Non-metals form acidic oxides while metals form __________.