An atom is silicon has a mass number of 28 and an atomic number of 14 how many protons and electrons and neutrons does this atom have and what is the election configuration for a silicon atom?

14, 14, 14. I have no idea what the second part of that question means but since the atomic number is 14, there are 14 protons and in an atom protons and electrons are equal. The mass number being 28 is the number of neutrons plus the number of protons. Since there are 14 protons, 28-14=14 neutrons and 14 electrons

If a hydrogen atom is neutral, it must also have  one electron. an oxygen atom (o) has an atomic number of eight (8). this means a neutral oxygen atom has eight protons and eight electrons. the element actium (ac) has an atomic number of 89, so it has 89 protons and 89 electrons in a neutral atom