State the periodic law. How did the periodic law lead to the periodic table?
Solution : The goal of the above problem is to answer the questions without referring to the table. So let’s discuss each sub-question and answer it. (a) What are the main subatomic particles that make up the atom Atom is the smallest particle of an element. An atom of an element further constitutes of subatomic particles. The three main subatomic particles that form an atom are protons, neutrons, and e lectrons. The center of the atom is calledthe ucleus. There are equal number of protons and electrons in an atom. Protons and neutrons make up the nucleus of an atom. Electrons are the negatively charged particles of atom, they balance the positive charge of the protons in the nucleus. (b) What is the relative charge (in multiples of the electronic charge) of each of the particles An a tom is made up of ositive ly a egatively charged particles. Protons a re positively charged and electrons a re egatively charged. The relative charge of a particle is a charge compared to other particle. The relative charge of a proton is +1. This indicates that the proton is the positively charged particle in an atom. The relative charge of an electron is -1 and it indicates electron is egatively charged particle. The relative charge of the neutron is 0, which indicates it is eutral, i.e it has no charge. (c) Which of the particles is the most massive Neutron is the most massive particle of an atom. Protons and neutrons have approximately the same mass, but neutrons are much more massive than protons. (d) Which is the least massive Among the particles , electrons are the least massive but takes up the most of the volume of an atom.