The characteristic bright-line spectrum of an element occurs when electrons A
move from lower to higher energy levels.

B
are lost by a neutral atom.

C
are gained by a neutral atom.

D
move from higher to lower energy levels.

At stp, what is the volume of 1 mole of co2?

Sulfuric acid is a polyprotic acid. write balanced chemical equations for the sequence of reactions that sulfuric acid can undergo when it's dissolved in water.

Scientists often have to deal with numbers that are either very large or very small. for example, the radius of the sun is approximately 696,000 kilometers, while bacterial cells are as small as 1.9 × 10-4 millimeters. express each number in an alternate form.