How is an emission spectrum of an element generated?
a when an electron in an atom is excited to a higher energy state.
b. when an electron in an atom is in the excited state.
c. when an electron in an atom returns from an excited state to a lower energy state.
d. when an electron in an atom is in the ground state.

You exhale co2 which is produced during cellular respiration.  co2 combines with the water in your blood's plasma to make up one half of the body's most important buffer pair, carbonic acid.  the more physical activity you engage in, the more co2 your body is producing.  you can see this by putting some of the cabbage indicator in a glass and then blowing bubbles into it through a straw.  can you see a change in the color of the indicator?

Phosphorous can form an ion called phosphide, which has the formula p3−. this ion can form an ion called phosphide, which has the formula p3−. this ion properties very similar to those of pforms when a phosphorus atom loses three protonsis called a cationcontains 18 electrons

Rays from the sun are not considered matter true or false