Question

1. if you heat most earth substances, what happens to their density? the density decreases 5. explain your answer to #4, why would that happen (think volume)?

Explanation:

When substances are heated, they generally expand (thermal expansion). Since density $
ho=\frac{m}{V}$ (where $m$ is mass and $V$ is volume), and mass remains constant during heating (no mass is added or removed in a closed - system heating process), an increase in volume $V$ leads to a decrease in density $
ho$.

Answer:

When most Earth substances are heated, their density decreases because heating causes thermal expansion which increases the volume of the substance while the mass remains the same. Using the density formula $
ho = \frac{m}{V}$, with $m$ constant and $V$ increasing, $
ho$ decreases.