Which of the following is the number of protons plus the number of neutrons? atomic charge mass number atomic number atomic isotope number

The number of protons plus the number of neutrons is the mass number.

The ionic charge depends on the number of electrons.

The atomic number is the number of protons.

Atoms can have different isotopic masses, but there is no such thing as atomic isotope number.

the answer is a

photosynthesis

the ozone layer acts as a filter for the shorter wavelength and highly hazardous ultraviolet radiation (uvr) from the sun, protecting life on earth from its potentially harmful effects. when the sky is clear, there is an inverse relationship between stratospheric ozone and solar uvr measured at the earth's surface.