Heat can be transferred through conduction, convection, and radiation. what is necessary in order for heat to be transferred by conduction?
a.
heat must be transferred in the form of currents.
b.
the objects must be in direct contact with one another.
c.
heat must be transferred through space.
d.
the substances must be liquids or gases.

What can happen to solar radiation when it enters earths atmosphere? check all that apply 1)it is absorbed by earth. 2)it is reflected by clouds. 3)it is reflected by glacial ice. 4)it is condensed into visible light. 5) is amplified by water molecules.

Compounds which are found naturally in the earth are called: a. ores b. composites c. rocks d.minerals

Some gamma ray bursts are hypothesized to come from mergers of neutron stars or black holes. if this hypothesis is correct, what else should we in principle be able to detect from such mergers? a. gravitiational waves b. x-ray bursts c. significant disruption of gas thousands of light-years away in the surrounding galaxy d. an "afterglow" of bright visible light, lasting for weeks