Question

A)State the number of valence electrons for the element O?
B) An element with 5 protons, has how many electrons?
C) If an element has 4 electrons and an atomic mass of 9, what element is it?
D)Chlorine has two naturally occurring isotopes: Cl-35 and Cl-37. Which isotope is more abundant if the atomic mass of chlorine is 35.45?

Answer 1

A) number of valence electrons is 6
B) number of protons is same as number of electrons
C) That elements is berilium
D)I think it is Cl-37 one