Gallium has a melting point of 30 °C and boiling point of 2403 °C. At which temperature below will gallium be a gas?
A) -25 °C
B) 25 °C
C) 250 °C
D) 2500 °C
The correct answer and explanation is :
The correct answer is D) 2500 °C.
Explanation:
To understand the behavior of gallium and determine the temperature at which it will be a gas, we need to consider its melting and boiling points.
- Gallium has a melting point of 30 °C, which means that at temperatures below 30 °C, gallium is in its solid form. At temperatures above 30 °C, it transitions from a solid to a liquid.
- Gallium has a boiling point of 2403 °C, meaning that at temperatures higher than 2403 °C, gallium will transition from a liquid to a gas.
The key concept here is understanding the phase changes of substances. A substance can exist in different phases (solid, liquid, gas) depending on the temperature:
- Below the melting point, gallium will be a solid.
- Between the melting point (30 °C) and the boiling point (2403 °C), gallium will be in its liquid state.
- Above the boiling point (2403 °C), gallium will be a gas.
Given the choices:
- A) -25 °C: At this temperature, gallium is below its melting point and will be a solid.
- B) 25 °C: This is still below the melting point of 30 °C, so gallium will be a solid.
- C) 250 °C: This is above the melting point but still below the boiling point, so gallium will be in the liquid phase.
- D) 2500 °C: This temperature is well above the boiling point of 2403 °C, so gallium will be in the gas phase.
Thus, gallium will be a gas at 2500 °C, which is above its boiling point of 2403 °C. Therefore, the correct answer is D) 2500 °C.