Question

define element and compound.any 5 points

Answer 1

Element is a basic form of matter that cannot be broken down into simpler substances by chemical reactions. Elements can be normally divided into metals, non - metals and metalloids.
For example, copper, oxygen, iron, hydrogen, chlorine, mercury, etc.

Compound is a substance composed of two or more elements, chemically combined with one another in a fixed proportion.They can be broken down into elements by chemical or electrochemical reactions.
For example, water, methane, sugar, salt, etc.

Answer 2

An element is a substance that is composed of atoms and molecules of one kind only. It has unique properties from other substances. It is characterized by an atomic number (and atomic weight) equal to the number of electrons or protons in the atom.
It is a pure substance. An element has unique physical and chemical properties. The elements are classified into a periodic table.
examples are $Hydrogen\ H_2\ and\ Oxygen\ O_2$

A (chemical) Compound is a substance in which atoms of one or more elements form bonds together making one molecule of the substance. The molecules remain stable together during a certain range of temperatures. Compounds may react with other elements or compounds forming different compounds and elements.

$Ammonia NH_3,\ water\ H_2O$are examples.