Understanding Chemistry!

Hello, My name is Siraj Zafar, and today I will help you understand Chemistry (as a subject). Chemistry is a branch of the gigantic tree of science. It is the study of the composition, the structure, the physical characteristics, and the change of matter. In other, more easy words, it is the study of chemicals and what they do. A few examples of chemicals are Na (sodium), Ca (calcium), and He (helium).

A very rough picture of the structure of an atom. The Brownish-red color is the nucleus, the yellow dots are protons, and the green dots are neutrons. the blue dots revolving around the nucleus are electrons. 

The nucleus of an atom contains the protons and neutrons. The electrons revolve around the nucleus. Protons, electrons, and neutrons are also known as sub-atomic particles. Memorize them as PEN. P for proton, E for electron, and  N for neutron. The proton is a positively charged particle with a relative mass of 1. The neutron is not charged as it is a neutral particle. It also has a relative mass of 1. The electron is a negatively charged particle but it only has a mass of 1/1850. In a neutral atom, the number of protons is always equal to the numbers of electrons.

This is the periodic table of elements. It arranges all of the known elements in the world by number of proton. We will study these in depth later on.

The periodic table will be studied in depth later on. The elements are arranged by it symbol, in the center, the number of protons or atomic number in the top left corner and the atomic mass, or total mass excluding electron mass in the bottom.