6. (a) Which of these means changing state from solid directly to gas? A condensing B freezing C melting D sublimating (b) An object has a mass of 7.22 × 10^2 kg and a volume of 2.69 × 10^3 m³ - Edexcel - GCSE Physics Combined Science - Question 6 - 2023 - Paper 2

To calculate the density, we use the formula:

$\rho = \frac{m}{V}$

Where:

• $m = 7.22 \times 10^2 \text{ kg}$
• $V = 2.69 \times 10^3 \text{ m}^3$

Calculating the density:

$\rho = \frac{7.22 \times 10^2 \text{ kg}}{2.69 \times 10^3 \text{ m}^3} \approx 0.268 \text{ kg/m}^3$

The unit for density is kilograms per cubic meter (kg/m³).

To convert the melting point of aluminium from Celsius to Kelvin, we use the formula:

$K = °C + 273$

Given that the melting point of aluminium is 660°C:

$K = 660 + 273 = 933 ext{ K}$