Answer:
A and C represent elements while B and D represent Compounds
Explanation:
chemical elements cannot be broken down into simpler substances by any chemical reaction. While A chemical compound is a chemical substance composed of many identical molecules composed of atoms from more than one element held together by chemical bonds
Answer: When the electrons in an element are more than the required, a bond is formed with other element which has deficiency of electron and in case when electrons are less in numbers the vice versa happens. Such kind of chemical bonds are known as ionic bond.
Explanation: