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.

Astudent wears sunglasses to her read a book more easily which wave interaction occurs as light passes from the air into the plastic lenses? a polarization b.refraction c.diffraction d. interference

Suppose you have a box. which of these is not necessarily a true statement regarding the relationship between the force applied to the box, the work done on the box, and the distance the box is moved? a. if the box is not moved, no force is being applied to the box. b. if no force is applied to the box, no work is done on the box. c. if work is done on the box, then a force is applied to the box. d. if work is done on the box, then the box is moved a distance.

At very high pressures, gases become and will eventually a) more dense; become hotter b) more dense; change to a liquid or solid c) less dense; combust d) less dense; turn into a liquid