Some of the gases in Earth's atmosphere, such as CO2, are called greenhouse gases. Greenhouse gases interact with sunlight in a way that traps heat in the atmosphere. By trapping heat, greenhouse gases help insulate Earth. The table below lists some important greenhouse gases and their atmospheric concentrations in units of parts per million (ppm), parts per billion (ppb), or parts per trillion (ppt).

Greenhouse gas Concentration in 2015

Carbon dioxide (CO2) 400 ppm

Sulfur hexafluoride (SF6) 9 ppt

Methane (CH4) 1,750 ppb

Nitrous oxide (N2O) 325 ppb

Use the data in the table to put the following greenhouse gases in order of atmospheric concentration.

Hint: A concentration of 1 ppm is 1,000 times more than 1 ppb, and 1 ppb is 1,000 times more than 1 ppt.

Imagine that a new planet is discovered with two moons of equal mass: moon a and moon b. the mass of the new planet is greater than the combined mass of its moons. moon a is farther away from the new planet than moon b. what is the planet's gravitational pull on moon a compared to the planet's gravitational pull on moon b? the planet's gravity repels moon a with a greater force than it repels moon b, which is why moon a is farther away. the gravitational pull on moon b is greater than on moon a because moon b is closer to the new planet than moon a. the gravitational pull on moon b is greater than on moon a because moon b is farther away from the new planet than moon a. the gravitational pull on moon a is the same as the gravitational pull on moon b because distance does not affect the planet's gravity.

Select the correct answer. wax is a nonpolar substance. in which type of substance is it most soluble?

Robert leaves a chocolate bar in his car while attending school all day. when he goes to his car in the afternoon, the bat has changed into gooey liquid. what happened to the chocolate bar