Chemistry is the study of the composition,

structure, and properties of matter and the changes it

undergoes.

Physical Properties-can be observed & measuredw/o changing the chemical makeup of the substance

Physical Properties of Water Water’s freezing point is 0oC Water is a universal solvent (Most substances dissolve in it).Water-based solutions

are called aqueous solutions. Water is clear, colorless, odorless, & tasteless Density-is a measure of the mass of a material in a

given volume. Water’s density is 1.00 g/mL

Density CalculationsFormula

Multiply both sides by v

To solve for mass

The "v's" cancel out

Mass formula

m = v x D   

To solve for volume

Divide both sides by density

The “D’s” cancel out

Volume formula

Practice Problems-Density A sample of aluminum metal has a mass of

8.4g.The volume of the sample is 3.2cm3.Calculate the density.

What is the volume of a sample of liquid mercury that has a mass of 76.2g, given the density of mercury is 13.6 g/mL?

What is the mass of a sample of material that has a volume of 55.1cm3 and a density of 6.72 g/cm3?

Pure substance-have uniform and definite composition can’t be broken down.

•Element – a fundamental form of matter with the same chemical and physical properties that can’t be broken down into any more unique parts by ordinary chemical or physical means

•Atom – the smallest particles of matter that retainsall of the properties of an element

ExampleLet’s say that I had a brick of pure gold. This would be an element, because no matter how many times I broke it’s many atoms apart, every atom would still be gold.

Elements

one of the 100+ pure substances

that makes up everything in the universe

Examples of Elements

H = Hydrogen

C = Carbon

O = Oxygen

N = Nitrogen

S = Sulfur

Na = Sodium

Ca = Calcium

K = Potassium

I = Iodine

Cl = Chlorine

P = Phosphorus

Molecules– are made of 2 or more different atoms combined by chemical bonding (glue that holds elements together to form compounds)

Compounds - 2 or more elements chemically combined to form a new substance with new properties

Molecules & Compounds

Two identical elements combine to form a molecule

This happens with the following elements:

1) H2

2) N2

3) O2

4) F2

5) Cl2

6) Br2

“GEN-U-INE DIATOMICS” CAN SERVE AS A GOOD MEMORY DEVICE FOR ALL COMMON DIATOMIC ELEMENTS. THE NAMES OF THE DIATOMIC ELEMENTS END IN EITHER GEN OR INE, AND U BETTER REMEMBER THEM.

DIATOMIC MOLECULES

Two Types of Mixtures Homogenous Mixtures – Do Not have visibly different partsColloid-mixture containing solid particles that are small enough toremain suspended Example-MilkSolutions-homogenous mixture of two or more substancesSolute-dissolved substance in a solution, usually the component presentin the smaller quantity Example: salt in waterSolvent-dissolving agent in a solution, usually the component present inthe larger quantity Example: Water Examples: Seawater

A mixture is a blend of two or more pure substances. Itcan be broken down into two or more pure substances

Heterogeneous Mixtures: – Has visibly different parts Suspension-mixture containing large,

dispersed solid particles that can settle out or be separated by filtration Examples: Chocolate Chip Cookies, Foul

Water Sample

Chemical symbols are the letters in the language of chemistry that represent elements and formulas that describe atoms, elements & compounds.

Chemical formula are the words in the language of chemistry that represents a different chemical substance.

Chemical equation are the sentences in the language of chemistry that summarize the details of a particular chemical reaction.

Chemical reactions are the breaking and forming of chemical bonds, causing atoms to become rearranged into new substances.

Chemical equations show the conversion of reactantsreactants (the molecules shown on the left of the arrow) into productsproducts (the molecules shown on the right of the arrow).

A + sign separates molecules on the same side

The arrow is read as “yields” Example

C + O2 CO2

This reads “carbon plus oxygen reacts to yield carbon dioxide”

Parts of a Chemical Equation

44 Al Al ((s)) + + 33 OO22 (g)(g) ---> ---> 22 AlAl22OO33 (s)(s)

Reactants-Reactants-the original (starting) substancesthe original (starting) substances

Products-Products-new substances formed from thenew substances formed from the

rearrangement of the reactant atomsrearrangement of the reactant atoms

The numbers in the front tell you how many moleculesThe numbers in the front tell you how many molecules

are represented they are called are represented they are called coefficientscoefficients..

The The subscriptssubscripts tells you how many atoms of a particular tells you how many atoms of a particular

element are in a compound. element are in a compound.

Chemical Equation

Solid (s)Solid (s) Gas (g)Gas (g) Liquid (l) Liquid (l) Aqueous solution (aq) Catalyst H2SO4

Escaping gas () Change of temperature ()

Symbols Used in Chemical Equations

Particulate Level Diagrams

CHEMICAL REACTIONSCHEMICAL REACTIONS

Reactants: Zn + IReactants: Zn + I22 Product: Zn IProduct: Zn I22

The charcoal used in a grill is basically carbon. Thecarbon reacts with oxygen to yield carbon dioxide. The

chemical equation for this reaction, C + O2 CO2,contains the same information as the English sentence

but has quantitative meaning as well.

CHEMICAL REACTIONSCHEMICAL REACTIONS

Protons p+ - positive

charge, in nucleus

Electrons - e- negative

charge, orbiting nucleus

Neutrons n0 – no

charge, in nucleus

+ +

+

Like charges repel

Unlike charges attract