Made of 1 type of atom.

Element

Begins with a capital letter, followed by a lower case letter. A short way of identifying an element.

​​Chemical Symbol

A substance formed by chemically bonding atoms from 2 or more different elements.

Compound

A short way to write the number of atoms and elements present in a compound.

​​Chemical Formula

Shows how elements rearrange to form new substances.

Chemical Equation

Always follows the element it goes with. The number in a chemical formula that tells us how many atoms of each element are present.

Subscript

Always goes before the molecule it represents. Tells us how many of that molecule is present in the chemical equation.

​​Coefficient

Elements:
H = hydrogen
O = oxygen

​Count the number of capital letters in the formula. That tells you how many elements are present.

​2 capital letters
2 elements

Numbers
2
No number

Look for subscript numbers

​2 hydrogen atoms
1 oxygen atom

​When there is no subscript number behind a chemical symbol, it means there is only one atom of that element.

Subscript number is 2
so there are 2 atoms of oxygen

​1 capital letter = 1 element

​chemical formula

​Electrically bonded by the electrons.