Test: Materials: Properties and Changes - Year 6 MCQ

The melting point is the specific temperature at which a solid changes into a liquid. For example, ice melts at 0 °C, and gold melts at 1064 °C.

Evaporation occurs when particles at the surface of a liquid gain sufficient energy to escape as gas. Unlike boiling, evaporation can happen at any temperature.

Metals are excellent thermal conductors because they transfer heat efficiently. Silver is the best thermal conductor among metals.

Pure water boils at 100 °C under standard atmospheric pressure. This is a characteristic property of water.

Melting ice is a reversible change because liquid water can be frozen back into ice without forming a new substance.

When a solute dissolves in a solvent, the resulting uniform mixture is called a solution. For example, salt dissolving in water forms a saline solution.

Stirring spreads solute particles faster into the solvent, increasing the dissolving rate. Increasing the surface area also helps, but among the given options, stirring is the direct correct choice.

In a chemical reaction, reactants undergo a change to form new products with different properties. For example, burning wood produces ash and gases.

The production of a visible gas when vinegar and bicarbonate of soda react is evidence of a chemical reaction occurring.

Heating a solvent like water adds energy, making particles move faster, which helps solute particles (sugar) dissolve more quickly.