Why is it necessary to classify element

The number of elements discovered has increased, making it difficult to remember the behavior and properties of these elements. Hence it is important to classify elements according to their properties.It helps us understand how different elements form different compounds

because u need two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei to form isotopes.

so since they all have the same shape? i mean maybe because m& m and reeses are both chocolates