3. Which of the following statements is correct?
X Х
1. doubling the pressure of a gas doubles its volume
2. 2.00 L of air at 227°C has twice the pressure of the same 2.00 L of air at -
23°C
3. 2.00 L of air at 100°C has twice the pressure of the same 2.00 L of air at
50°C
4 halving the pressure of a gas halves its volume

3. 2.00 L of air at 100°C has twice the pressure of the same 2.00 L of air at  50°C

Explanation:

3. 2.00 L of air at 100°C has twice the pressure of the same 2.00 L of air at  50°C

This is correct;

According to Gay-Lussac Law,

The pressure of given amount of a gas is directly proportional to its temperature at constant volume and number of moles thus, by increasing the temperature pressure is also goes to increase in the same ratio.

All other options are incorrect,

1)  doubling the pressure of a gas doubles its volume

This is incorrect because by increasing the pressure volume is going to be decreased.

2)  2.00 L of air at 227°C has twice the pressure of the same 2.00 L of air at  23°C

This is also incorrect because 2 L air at 227 °C will have the pressure more than twice time as compared to the 2L air at 23°C.

4. halving the pressure of a gas halves its volume

This is incorrect because halving the pressure of gas increasing its volume.

d) a person who learns about the world by observing it.

explanation:

scientist are people who discover why and how things are done and made in the world.