On which basis is the physical classification of matter made?

Correct answer: Physical state

Physical classification groups matter according to its observable physical state, mainly solid, liquid, or gas. Therefore, option B is correct. This grouping is based on properties such as shape, volume, particle spacing, and freedom of particle movement, without requiring a change in chemical composition. A chemical formula identifies composition, atomic number identifies the number of protons in an element, and molecular mass gives a mass value; none of these is the primary basis for the basic physical classification of matter. The word physical is the key clue because the classification uses physical form and behaviour.