What is the maximum number of electrons that can occupy the fourth principal energy level of an atom?

What is the mass of 0.46 mol of mgcl2

Which of the following units is not an official si unit

Question 3(multiple choice worth 4 points) (04.04 lc) what does it mean when an element is reduced? it empties a valance shell, reducing its atomic radius. it gains electrons, reducing its overall charge. it increases electronegativity, reducing its ability to bond. it loses electrons, reducing its electron number.