What is the mass number of an atom that consists of 20 protons, 20 neutrons, and 18 electrons?

Choose all the answers that apply. fluorine (f) has an atomic number of 9 and an atomic weight of 18.99. fluorine has a. 9 protons b. 10 neutrons c. 18 electrons d. an atomic mass of 19 e. at least one isotope

According to thomson, the atom is a positively charged cloud with electrons scattered throughout. what would the alpha particles do when they hit the foil if thomson were correct

Calculate the number of grams of sodium in 3.00 g of each sodium-containing food additive.