Answer
a) covalent compound.
b) covalent compound.
c) ionic compound.
d) covalent compound.
Work Step by Step
Metals have the tendency to emit electron and form cation. On the other hand, non metals have the tendency to accept that electron and form anion. That's how ionic bond is formed and the compound becomes ionic compound. If both the elements are non metal they can share electrons to form covalent bond rather than emit or accept the complete electron. That's how covalent compound is formed.
a) In this case, C and H both are non metal. So, they are connected via covalent bond. So, the compound is covalent compound. Carbon always has the tendency to form covalent bond with other element.
b) In this case, Cl and Br both are non metal. So, they can share electron to form covalent bond. Hence the compound is covalent.
c) In this case, Cu is a metal and O is non metal. So, Cu emits two electron from valence shell to form $Cu^{2+}$ ion and O accepted that two electrons to form $O^{2-}$ ion. So, they form ionic bond. Hence, the compound is ionic.
d) The compound consists of Carbon. As carbon has the tendency to form covalent bond with other element, the compound is covalent.
