Which of the following statements about the interaction of earth’s systems is true?
a.
the interaction between earth’s systems is limited to a response to human activity.
b.
the earth’s system interact using positive feedback only.
c.
the earth’s systems interact using negative feedback only.
d.
all of the earth’s systems interact with each other.

Which is true of chemicals? a. things containing chemicals always cost a lot of money. b. chemicals are never dangerous. c. chemicals are in many substances in a home. d. chemicals are rarely found on earth.

As you move from right to left on the periodic table the atomic radius fill in the blank

Listen base your answer to the question on the information below.propane is a fuel that is sold in rigid, pressurized cylinders. most of the propane in a cylinder is liquid, with gas in the space above the liquid level. when propane is released from the cylinder, the propane leaves the cylinder as a gas. propane gas is used as a fuel by mixing it with oxygen in the air and igniting the mixture, as represented by the balanced equation below.c3h8(g) + 5o2(g) → 3co2(g) + 4h2o() + 2219.2 kja small amount of methanethiol, which has a distinct odor, is added to the propane to consumers detect a propane leak. in methanethiol, the odor is caused by the thiol functional group (–sh). methanethiol, ch3sh, has a structure that is very similar to the structure of methanol.what is the correct structural formula for a molecule of methanethiol