An atom is the smallest particle of an elements. Atoms are too small to been seen with a microscope. Each atom has properties that allow elements to combine with other elements.
Electrons move around the nucleus and have a negative charge.
Protons have a positive eletrical charge. They are found in the nucleus of the atom.
Neutrons have no charge. Along with the protons, they are found in the nucleus of the atom.
The order of the periodic table is important.The columns are arranged so elements in each column have similar chemical properties.
Each row is set up with the number of protons an element has.
Atoms combine with other atoms to form molecules. For eg; A water molecule is made up of two hydrogen molecules and one oxygen molecule. It is the smallest particle of a substance made of atoms of that substance.
Air is a combination of molecules (Oxygen/nitrogen and other gases)
Compounds are a type of matter made of more than one element. Most things are compounds. Properties of compounds are different than its elements. Electrons can bond to form compounds. H2O- 2 hydrogen- 1, oxygen (number comes after the element).
Salts are compounds whose molecules are held together by opposite charges. The properties of salts are different from the elements that they are made up of. Table salt is made up of sodium and chlorine.