BASIC CHEMISTRY

_______________ - anything that has mass and occupies space

_______________ - the capacity to move matter, to do work

PROPERTIES OF MATTER:

_______________ - the measure of the amount of matter in an object

_______________ - a measure of the pull of gravity on mass

_______________ - size, shape, texture, color, hardness, ability to conduct electricity, boiling point, etc.

_______________ - how a substance acts when it combines with other substances

_______________ - substances can change physically without changing chemically

States of Matter:

1. _______________ - molecules are densely packed, have a definite shape, and a definite volume

2. _______________ - molecules are held together loosely, no definite shape, define volume

3. _______________ - molecules are practically free, no definite shape, no definite volume (can be compressed or expanded)

4. _______________

Matter can change from one state to another without changing chemically.

Chemical Changes change substances into entirely different substances.

ATOMS

_______________ = the basic building blocks of matter

Atoms are made of 3 particles:

1. _______________ - positively charged

2. _______________ - neutral

3. _______________ - negatively charged

The protons and neutrons form the core or nucleus of the atom. The electrons circle or orbit the nucleus.

In most atoms the number of protons and electrons is equal so the atom is neutral.

_______________ - are atoms that have gained or lost an electron so they have a positive or negative charge.

ELEMENTS

_______________ - a substance that cannot be changed into a simpler substance by chemical means.

There are 92 naturally occuring elements.

Other artificial elements have been created.

Each element is made of atoms with a different number of protons from any other element.

THE PERIODIC CHART

Each element has been given a symbol.

_______________ = Oxygen

_______________ = Hydrogen

_______________ = Carbon

_______________ = Nitrogen

_______________ = Calcium

_______________ = Aluminum

_______________ = Iron

_______________ = Sodium

_______________ = Gold

Elements are arranged in rows in order of their atomic number.

_______________ = the number of protons in one atom of that element

_______________ = the number of protons + the number of neutrons in one atom.

_______________ - regions around the nucleus where electrons travel

first energy level can contain up to _______________ electrons

2nd energy level can contain up to _______________electrons

3rd energy level can contain up to _______________electrons

4th energy level can contain up to _______________electrons

5th energy level can contain up to _______________electrons

6th energy level can contain up to _______________electrons

Atoms whose outer shell is contains _______________ electrons are the most stable.

(except for atoms with only a few electrons)

FORMATION OF CHEMICAL BONDS

_______________ - the force that holds atoms together

_______________ - bonds caused by the transfer of electrons

Example: NaCl

_______________ - bonds caused by sharing electrons

Example: Water

Atoms may share one pair of electrons (single bonds) or two pairs (double bonds)

COMPOUNDS AND MOLECULES

_______________ = 2 or more elements that are combined chemically.

Compounds have special properties that differ from the properties of their individual elements.

Example - Salt (NaCl)

Na - Sodium reacts explosively with water.

Cl - Chlorine is a poisonous green gas.

Some elements form many compounds.

Some elements do not form compounds. They are said to be _______________.

The smallest unit of compound is a _______________.

A molecule is a unit of a substance that consists of 2 or more atoms combined chemically.

_______________ - tells the number of each kind of atom in a molecule.

Examples:

O₂ - an oxygen molecule

H₂ - a hydrogen molecule

CO₂ - a carbon dioxide molecule

H₂O - a water molecule

The molecular formula also allows you to determine the weight of a molecule by adding the mass of all the atoms in the molecule.

MIXTURES

Mixtures consist of different substances that are not combined chemically.

They can contain solids, liquids, or gases

_______________ - a homogeneous mixture of 2 or more substances

_______________ - a substance that will dissolve other substances

_______________ - a substance that dissolves in a solvent

_______________ - the amount of solute dissolved in a solution.

_______________ - when a solvent holds all the solute that it can hold

_______________ - a mixture in which particles are temporarily mixed together.

Suspensions look cloudy. Solutions look clear.

Suspended particles will eventually sink.

_______________ - a mixture in which the suspended particles are larger than solutes but do not sink to the bottom like suspensions.

Example : jello

Gel - the semisolid state

Sol - the fluid state

ENERGY AND CHEMICAL CHANGE

_______________ - energy of position or composition.

_______________ - energy of motion

Any process of change involves the conversion of one form of energy to another.

CHEMICAL REACTIONS

Chemical reactions are caused when atoms break existing bonds and form new ones.

The energy required to break existing bonds and start a reaction is called _______________. Heat is the most common form.

Example: heating sugar

_______________ - give off more energy than they use up

_______________ - use up more energy than they give off

_______________ - symbols and formulas that show what happen in chemical reactions

_______________ - the substances that enter the reaction

_______________ - the substances that are produced during the reaction