The random movement of a substance from an area of higher concentration to an area of lower concentration is called

Correct Answer: A

Rationale: Diffusion is the passive movement of substances down their concentration gradient.

Correct Answer: D

Rationale: Chromosome number reduction occurs in meiosis, not mitosis.

Correct Answer: C

Rationale: Elements are the fundamental substances that make up all matter, existing in various states (solid, liquid, gas).

Correct Answer: C

Rationale: Isotopes vary in neutron number but have the same proton number (atomic number).

Correct Answer: A

Rationale: Water has a high heat capacity, absorbing large heat amounts with small temperature changes.