Classify each pure substance as an element or a compound.
(b) baking soda (sodium bicarbonate)
An element is a substance consisting of atoms which all have the same number of protons - i.e. the same atomic number. Elements are chemically the simplest substances and hence cannot be broken down using chemical methods.
A compound is a substance formed when two or more chemical elements are chemically bonded together. Two types of chemical bonds common in compounds are covalent bonds and ionic bonds