The___of an element is the number of_Of an atom of that element. Fill in the blanks

A atomic mass, electrons in the nucleus

B mass number, neutrons in the nucleus

C mass number, protons plus neutrons number in the outermost energy level

D atomic number, protons in the nucleus

Iknow #2 is d. i just need to know why

Three cards with holes are arranged in a straight line. a light is shined through the first card’s hole and travels through all three cards. what does this tell you about light rays? a) that light is reflected b) that light is refractive c) that light travels in a straight line d) that light does not travel in a straight line

What three things determine the shape and size of a puddle when water is poured out onto a surface