Tion 4 Hydrogen gas (Hz) can be found in trace amounts in Earth's atmosphere. Which of these
statements describes a physical property of hydrogen?
Choose the correct answer.
1 Hydrogen is found in acids.
2 Hydrogen gas is highly. flammable.
3 Hydrogen reacts with oxygen to form water.
4Hydrogen gas is less dense than oxygen gas.

answer: the exterior temperature of commercial jet planes as they leave the stratosphere and return to the ground increases steadily.

explanation:

the lower most layer of atmosphere is troposphere which extends from 0 to 12 km above the surface of the earth. the temperature initially decreases as distance is increased from the earth's surface. commercial jets fly in lower part of the stratosphere. the stratosphere extends upto 50 km. the temperature in stratosphere starts rising again due to presence of ozone which traps the uv rays.

thus, when the planes leave the stratosphere and return to the ground, the exterior temperature increases steadily.