Question

bromine, a liquid at room temperature, has a boiling point of 58°c and a melting point of −7.2°c. bromine can be classified as a compound. impure substance. mixture. pure substance.

Explanation:

1. A compound is a substance made of two or more different elements chemically bonded. Bromine (Br₂) is a diatomic molecule of the same element, so it's not a compound.
2. An impure substance has other substances mixed in, resulting in variable properties (like a range of melting/boiling points). Bromine has a definite boiling (58°C) and melting point (-7.2°C), so it's not impure.
3. A mixture consists of two or more substances physically combined, with variable composition and properties. Bromine is a single substance, not a mixture.
4. A pure substance has a definite and constant composition, with fixed melting and boiling points. Bromine (Br₂) has fixed melting (-7.2°C) and boiling points (58°C), so it's a pure substance (specifically an element in this case).

Answer:

D. pure substance