The Chemical Basic of Life

Element

Pure substance that can’t be broken down into any other substance.

Know that Oxygen, Carbon, Hydrogen and Nitrogen are the most abundant elements in living organisms.

Compound

A substance containing 2 or more chemically bonded elements.

Atom

Smallest possible piece of an element

Protons

Sub-atomic particles with a POSITIVE electrical charge. Located in the nucleus.

Neutrons

Sub-atomic particles that are NEUTRAL (that means they have NO electrical charge.) Located in the nucleus.

Electrons

Sub-atomic particles with a NEGATIVE electrical charge. Located in spherical orbitals surrounding the nucleus.

Atomic Number

Tells us the number of protons in the nucleus of each atom of that element.

Mass Number

Tells us the total number of protons and electrons in the nucleus of each atom of that element.

How to Discover the Number of Neutrons of a ion

Subtract the Atomic Number from the Mass Number. Example This is the way Phosphorus looks on the periodic table.
Number of Protons: 15
Number of electrons: 15
Number of neutrons: 16
(31-15=16)
Mass Number: 31
Atomic Number: 15

NOTE!

Remember Atoms have the same number of electrons as protons (so the atomic number also tells you how many electrons an atom of that element has)

Electrons per Energy Level Orbitals

The first energy level orbital can hold 2 electrons, the second energy level orbital can hold 8 electrons, and the 3rd energy level orbital can hold 8 electrons

Ionic Bond

A bond which occurs when one atom transfers and electron to another atom.

Covalent Bond

A bond which occurs when 2 atoms share electrons.

Ion

An atom that has gained a positive or negative electrical charge as a result of gaining or losing an electron.

Activation Energy

The minimum amount of energy needed for a chemical reaction to occur.

Enzyme

A biological catalyst that speeds up biological chemical reactions.

Molecule

2 or more atoms covalently bonded to each other.

Why is Water a Polar Molecule?

In a molecule of water, the electrons are not shared equally between oxygen and hydrogen
The 8 positively charged protons in the oxygen atom's nucleus pull much harder on the electrons than the one positively charged proton in the nuclei of the hydrogen atoms.
So the electrons spend more time in the Oxygen atom's orbitals than in the orbitals of the hydrogen atoms.
Because of the negatively charged electrons are pulled more strongly towards the Oxygen's atoms nucleus, that side
A molecule(like water molecules), in which opposite sides have opposites electrical charges is called a POLAR MOLECULE.

Cohesion

The tendency for water molecules to stick together.Example: Cohesion cause surface tension on the surface of water, allowing some insects to appear to walk on water…. The bonds between the water molecules are too strong to be broken by the weight of the insect.

Adhesion

The type of attraction that occurred between a water molecule and a non-water molecule.Example: Water molecules are attracted to the molecules that make up the lining of tree roots, helping the water to move up in to the tree.

Acids, Bases, and Aqueous Solutions

When added to an aqueous solution, some chemical compounds add additional H= ions to the solution, while other remove H+ ions from solution.
Acid: A chemical compound that adds H+ ions to a solution
Base: A chemical compound that remove H+ ions from a solution