Why do ionic compounds conduct when dissolved and covalent compounds do not?

Elements in group 2 are all called alkaline earth metals. what is most similar about the alkaline earth metals?

Structure of the atoms: discovery of the nucleus in 1909i need answering all of these questions

Covalent bonds generally form when the bonded elements have a difference in electronegativity less than 1.5. subtract the electronegativities for the following pairs of elements and predict whether they form a covalent bond. electronegativity difference of c and c: ionic covalent electronegativity difference of mg and cl: ionic covalent