Chemistry of Life

All matter is made up of atoms.

Matter is anything that has mass and takes up space.

protons

neutronselectrons

Matter can be composed of an element, a compound, or a mixture.

Aluminum, Al

Element – a pure substance made of one type of atom, and it cannot be broken down.

There are 109 elements.

96% of the mass of a human is made of only 4 elements –

carbon, hydrogen, oxygen, nitrogen.

OHH

Compound - a pure substance that is composed of atoms of two or more different elements joined by chemical bonds.

Most elements do not exist alone. Elements combine to form compounds.

ELEMENT COMPOUND

MIXTURE

OHH

Water, H2O

Chemical bondChemical bond

The elements that make up a compound are held together by chemical bonds.

A chemical bond is a force of attractionbetween two atoms.

There are two types of chemical bonds:

• Covalent bond

• Ionic bond

(1) Covalent bond – chemical bond between atoms in which electrons are shared.

Covalent bond

OH H

(2) Ionic bond – chemical bond between atoms in which electrons are transferred to other atom.

Ionic bond

Cl-Na+

Acid Base

Strongest acid

Strongest Base