Chemistry

electrons

subatomic particles that orbits the nucleus at various levels

-called layers shells, or clouds

Stable Electron Arrangement

valence shells are FULL

Valence Shell

outermost electron shell

Valence Electrons

electrons occupying the valence shell

First Shell of atom does what?

1 orbital; (s) holds max of 2 electrons

Second Shell of atom does what?

2 orbitals; (s,p) holds max of 8

Third Shell of atom does what?

3 orbitals; (s,p,d) holds a max of 18

Fourth Shell of atom does what?

4 orbitals; (s,p,d,f) holds max of 32

Atoms lose and gain electrons trying to fill what?

their valence electrons

Gains Electrons

negatively charged ion

-anion (-)

Loses Electrons

positively charged ion

-cation (+)

Atoms move towards what?

stability

-once stable, atoms do not react with other atoms

All matter is made up of what?

atoms

Atoms consists of what?

1. nucleus: protons, neutrons,

2. electrons: surround the nucleus in an electron cloud

Atomic Radius

average distance between the nucleus and outermost electron.

-the further the distance from the nucleus, the greater the energy

Protons

positive charge

1 atomic mass unit

Neutron

no charge (neutral)

1 atomic mass unit

Electrons

negative charge

0 atomic mass unit

Isotopes

atoms of the same element with different numbers of neutrons

Stable, non-radioactive isotopes

no decay

Unstable, radioactive isotopes

decays; unstable nuclei

Atomic Mass

protons + neutrons

Number of Protons =

atomic number

Number of Neutrons =

atomic mass - atomic number

Number of Electrons =

atomic number

Chemical Bonding

a union between electrons of atoms

Ionic Bond

formed when one or more electrons are transferred from one atom to another

ex: Na+ + Cl- = NaCl

Covalent Bond

a chemical bond that involves sharing a pair of electrons between atoms in a molecule

Non Polar Covalent Bond

equal sharing of electrons

ex: O2

Polar Covalent Bond

electrons are not shared equally

ex: H2O

Hydrogen Bond

weak attraction between a hydrogen atom and another atom

Intermolecular

between molecules

Intramolecular

within a molecule

Alikali Metals

lithium, sodium, potassium

Alkaline Metals

beryllium, magnesium, calcium, strontium, barium, radium

Transition Metals

iron, copper, nickel

Basic Metals

thorium, uranium, plutonium

Sentimental (Metalloids)

boron, silicon, germanium, antimony, polonium

Nonmetal

oxygen, sulfur

Lanthanide

lanthanum

Actinide

actinium

Halogen

fluorine, chlorine, bromine, iodine, astatine

Noble Gases

helium, neon, argon, krypton, xenon, radon

Element

the most basic type of matter

What is the smallest unit of an element?

atom

Compound

chemical combination of 2+ elements

Molecule

smallest independent unit of an element or compound

Diatomic Elements

elements that exist naturally in pairs

ex: hydrogen (H2), nitrogen (N2), Oxygen (O2)

Elements + Compounds are represented by?

chemical symbols

Matter

substances that have mass + occupy space

What are the 4 states of matter?

solid, liquid, gas, plasma

Solids

definite shape and volume

Liquids

constant volume, no fixed shape

Gas

does not have a definite volume or shape

Molecular Motion

vibrate around

fixed position

Molecular Motion

move around freely (liquid)

rapid moving; spread far apart (gas)

Solid to Liquid =

melting

Liquid to Solid =

freezing

Liquid to Gas =

vaporization/evaporation

Gas to Liquid =

condensation

Solid to Gas =

sublimation (ex. dry ice)

Gas to Solid =

deposition (crystallization)

Physical Property

any property of matter that can be observed or measured

Intensive Property

does not change depending on the amount off matter present

ex: boiling point, melting point, color, specific heat

Extensive Property

does change depending on the amount of matter present

ex: mass, volume, weight, energy, electrical charge

Mass

a measure of the specific amount of molecules

Weight

a measure of the earth's gravitational pull on an object

Volume

a measure of the amount of space occupied

length x width x height

Density

a measure of the amount of mass per unit volume

-formula: mass/volume

Chemical Property

properties of any material that are present during a chemical reaction or chemical change

Chemical Properties depend on what?

the chemical reactivity of the substance

When a substance chemically reacts with another substance it forms what?

a new substance with a new identity

Chemical properties can not be recovered by what?

means of a physical change (such as freezing or boiling)

Chemical reactions are represented by what?

chemical equations

Chemical Reactions

occurs when particle collide with each other under the right conditions

Activation Energy

the amount of energy required for a specific reaction to occur

Catalyst

substance that speeds up the rate of a chemical reaction

Inhibitors

slow down reaction rates

Reaction Rate

the rate at which reactants change into products over time

Chemical Equilibrium

reversible reaction

Le Chatilier's Principle

body attempts to restore equilibrium when a stressor is applied

-described as shifting right or shifting left

Basic Layout Chemical Reaction

reactants, reactions, products

What are the five basic chemical reactions?

synthesis, decomposition, single replacement, double replacement, combustion

Synthesis Reaction

a reaction in which two or more substances combine to form a new compound

Decomposition

a chemical reaction that breaks down compounds into simpler products.

Single Replacement

one element replaces another element in a compound

Double Replacement

a chemical reaction where two elements in different compounds trade places

Combustion

the process of burning something

Chemical Equations

occurs when particles collide with each other under the right conditions

Coefficient

the number before the element that indicates the ratio of reactants (in terms of moles)

Water is cohesive

water sticks to water

Water is adhesive

water molecules stick to other surfaces

Solution =

solute + solvent

A solution is formed when...

a liquid mixture (one or more solutes) dissolves in a solvent

The more solute dissolved, the more ......... the solution

concentrated

Hydrophilic

water loving

Hydrophobic

water fearing

Saturated Solution

max amount of solute dissolved

Unsaturated Solution

less than the max amount of solute dissolved

Supersaturated Solution

more solute than is possible