Answer:
1. Elements have only 1 type of atoms
2. Atomic Number
3. Atomic Mass
4. Isotopes
5. Allotropes
Explanation:
An element is a pure chemical substance made of same type of atom.
Elements are distinguished by their name, symbol, atomic number, melting point, boiling point, density and ionization energies. In the Periodic Table, elements are arranged according to their atomic number and they are grouped according to similar chemical properties and are depicted by their symbols.
<em>1. Elements have only 1 type of atoms</em>
<em>2. Atomic Number</em>= Number of protons is also indicative of electric charge or number of electrons present in the nucleus which determines chemical properties of the element.
<em>3. Atomic Mass</em>= the atomic mass of the element which is the total number of protons and neutrons in the nucleus of an atom of the element.
<em>4. Isotopes</em>= isotopes of an element have the same number of protons in their nucleus but differ in the number of neutrons. Naturally occurring elements have more than one stable isotope. Thus isotopes have similar chemical properties (due to same number of protons) but different nuclear properties (due to different number of neutrons).
<em>5. Allotropes</em>= atoms of an element can form bonds with each other in more than one way leading to difference in their chemical properties
