Question

exam lesson name: states of matter
exam number: 700698rr
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▶ exam instructions

question 7 of 20 :
select the best answer for the question.

1. density is related to temperature. for example, hotter gases tend to be ______ dense compared to colder gases.

○ a. more
○ b. less
○ c. inversely
○ d. equally

□ mark for review (will be highlighted on the review page)

Explanation:

To solve this, we recall the relationship between temperature, volume, and density for gases (from the kinetic theory of gases). When a gas is heated (temperature increases), its particles move more, leading to an increase in volume (assuming constant pressure, via Charles's law or ideal gas law \( PV = nRT \); if \( T \) increases and \( P \) is constant, \( V \) increases). Density is defined as \(
ho=\frac{m}{V} \). Since mass (\( m \)) of the gas remains constant (closed system) and volume (\( V \)) increases with higher temperature for gases, the density (\(
ho \)) will decrease. So hotter gases have less density than colder gases. Option A is incorrect (more dense would require smaller volume, but hotter gases expand). Option C is a relationship type (inversely related) but not the correct descriptive term for the blank. Option D is incorrect as density changes with temperature for gases.

Answer:

B. less