Elements And Atomic Number

                          Many different types of atoms are called elements. Each element has a unique set of physical and chemical properties. Elements are a type of matter that can not be broken down into a simpler substance by chemical reaction. Some familiar elements are oxygen, carbon, sodium, gold, and hydrogen.

                          Elements are identified by the number of protons in their nucleus, known as the atomic number ( Z ). An element's atomic number ( Z ) also indicates the same number of electrons in the neutral atom.

For Example :

Hydrogen                                                                    Helium

Z = 1                                                                           Z = 2

Proton - 1                                                                    Proton - 2

Electron - 1                                                                 Electron - 2

(Remember atoms have an equal number of protons and electrons.)

                All elements are organized according to their atomic number in the periodic table. In the periodic table, the order of an element's atomic number increases from left to right and top to bottom. Elements are further organized as columns based on their properties. Elements in the same column have similar physical and chemical properties. Many elements are represented by their English names and chemical symbols.

Example:

Hydrogen - H

Helium - He

            Some elements are represented by their Latin names and chemical symbols. 

Example:

Mercury - chemical symbol Hg. It comes from the Latin name of Hydrargyrum.

Lead - chemical symbol Pb. It comes from the Latin name of Plumbum.

                In the periodic table, the boxes of each element will always contain atomic number, chemical symbol, name, and atomic mass.

Explanation:

                 At the top of the box Hydrogen atomic number is 1. Below that Hydrogen chemical symbol H followed by its name Hydrogen. The bottom number is the Atomic mass. Hydrogen atomic mass 1.008

Atomic Structure ( Atoms )

 Atomic Structure:

       The arrangements of protons, neutrons, and electrons within an atom.

What are atoms?

    Atoms are basic units of matter and building blocks of everything in the universe. They maintain all the properties of chemical elements. Atoms comprise smaller subatomic particles called protons, neutrons, and electrons.

Structure of atoms:

            outside the nucleus, we have electron clouds. The dense region at the center of an atom is the nucleus. It's made up of protons and neutrons. Neutrons have no charge ( neutral ). Protons are positively charged (1+). Electrons are negatively charged ( 1- ).

       The unit we used to express the masses of subatomic particles is the abbreviation of unified atomic mass unit ( u ) AMU. Protons and neutrons have similar mass unit 1u. All the mass of an atom is the nucleus not in the electron cloud.