Why do scientists use models to study atoms?

Which function is performed by earths atmosphere? a. ultraviolet rays are prevented from reaching the ozone layer. b. earths temperature is raised and moderated by trapping in heat c. charged particles from the sun are prevented from reaching earth. d. magnetic charges from space are prevented from reaching earths surface.

In salt water solution, the salt is the blank

What mass of natural gas (ch4) must you burn to emit 276 kj of heat?