Chemistry Notes

2012 - 2013Ms. Feffer, Mr. Sharp, and Mrs.

Wingate

Matter Anything that has a mass and a volume

Matter

Physical Propertie

s

Chemical Propertie

s

Are used to classify elements are boiling point, melting point, color, hardness, and density.

Used to separate elements from each other including flammability, reactivity with acids, or reactivity with oxygen.

Physical & Chemical

Physical Change

Chemical Change

• Changing from one state to another is a physical change.

• If a new substance is formed it is a chemical change.

Physical vs. Chemical Change

Images are from http://www.chem4kids.com

Atom The building block of Matter

Consist of Protons (+), Electrons (-), and Neutrons (N).

Very Small

Images are from http://www.chem4kids.com

Moleculeo Consist of 2 or more

atoms of the same element, or different elements, that are chemically bound together.o In the animation below, two

nitrogen atoms (N + N = N2) make one Nitrogen molecule.

Molecule

Pure Substance

o A substance made up of only ONE type of particle

o Elements are pure substances.

Example: Every particle in a 5g gold nugget is like every other particle of gold, no matter where they are found

Pure Substance

Elements

o Consist of only one kind of atom.

o Cannot be broken down into smaller type of matter by either physical or chemical means.

o Can exist as either atoms or molecules

Element

Composition Pie Chart

By percent, the Earth breaks down as follows:

Oxygen-O2 46.6%Silicon-Si 27.7%Aluminum-Al 8.1%Iron-Fe 5.0%Calcium-Ca 3.6%Sodium-Na 2.8%Potassium-K 2.6%Magnesium-Mg 2.1%others 1.6%

Abundance of elements in the Earth

The following pie chart shows the percentage by mass of elements in the Earth's crust.

Properties of

Compounds

Compounds, like elements, can be identified by their own physical and chemical properties.

Atoms of 2 or more different elements bound together

Can be separated into elements chemically, but not physically.

Compounds

In the animation above, water (H20)

is a compound made of Hydrogen

and Oxygen.

Animated images and notes from http://www.chem.purdue.edu/gchelp/atoms/elements.html

Question: How is an element different from a compound?

Answer:

Element =Examples: Gold (Au),

Silver(Ag), Oxygen (O), Iron (Fe)

Compound = Example-Flouride ( ),Water (H2O), Carbon Dioxide

(CO2)

Answer:

A pure substance that canNOT be separated into simpler substances by physical or chemical means

is composed of two or more elements that are chemically combined.

Element vs. Compound

Elements have:

o Unique properties that do not depend on the amount of the element present

Elements

Elements are identified by 3 main categories

oMetals

oNonmetals

oMetalloids

Elements Are Grouped by:

The Three Groups of Elements

Metals Nonmetals MetalloidsShiny Dull Some shiny,

some dullMalleable and ductile

Brittle and unmalleable

Somewhat malleable and ductile

Good conductors of electricity and heat

Poor conductors

Semi-conductors

Metalso They are all grouped

together on the left hand side of the Periodic Table.

o Not all metals are exactly alike, but they do have some properties in common.

o **Metals are elements that are usually shiny and good conductors of electricity and heat.

Elements Are Grouped by:

Metalso Metals are also

malleable (can be hammered into thin sheets).

o Chemical property of metal is its reaction with water which results in corrosion.

o Metals are ductile, or can be drawn into thin wires.

o Examples: Iron (Fe) and Copper (Cu).

Elements Are Grouped by:

Nonmetalso Usually dull and poor

conductors of heat and electric current.

o Tend to be brittle and unmalleable.

o Many non-metals are gases

o Nonmetals are located to the right of the “zig zag line” on the Periodic Table.

o Examples: Neon (Ne) and Carbon (C)

Elements Are Grouped by:

Metalloids●Share properties of both

metals and nonmetals.●They conduct heat and

electricity better than non-metals but not as well as metals.

●Can be shiny or dull.●Somewhat malleable

and ductile.●Examples:

Silicon (Si) Arsenic (As).

Elements Are Grouped by:

Metals are located to the left, non metals to the right and metalloids touch both side of the “zig zag” line on the periodic table.

Non- Metals

Metals

Metalloids

Looking at the Periodic TableNotice that the Largest portion of

Elements in our Earth come from the first 20 elements in the Periodic Table

Dmitri Mendelee

v

In 1869, Dmitri Ivanovitch Mendeléev created the first accepted version of the periodic table.

He grouped elements according to their atomic mass, and as he did, he found that the families had similar chemical properties. 

Blank spaces were left open to add the new elements he predicted would occur. 

Creator of Periodic Table

Properties of

Compounds

oCompounds, like elements, can be identified by their own physical and chemical properties.

o The compound Water is composed of Hydrogen and Oxygen chemically bonded together.

*Remember*

Properties of

Compounds

Can be broken down into simpler substances (elements or simpler compounds) Only through chemical changes

Examples:Water can be broken down

into hydrogen and oxygen through electrolysis

Carbonic acid breaks down into carbon dioxide and water when you open a soda

*Remember*

Compounds you need to know!

Compounds- The way a

compound is written is called it’s

FORMULA

Familiar CompoundCompound Elements Combined

Table Salt (NaCl)

Sodium and Chlorine (Na + Cl)

Water (H2O) Hydrogen and Oxygen (H + H + O)

Hydrocloric Acid (HCl)

Hydrogen and Chlorine (H + Cl)

Carbon Dioxide (CO2)

Carbon and Oxygen (C + O + O)

Methane (CH4)

Carbon and Hydrogen (C + H + H + H + H)

Baking Soda(NaHCO3)

Sodium, Hydrogen, Carbon, and Oxygen (Na + H + C + O + O + O)

Comes from…

oSodium – soft, silvery white metal that reacts violently with water

oChlorine – poisonous, greenish yellow gas

Sodium Chloride (table salt)

Precipitate

Is when a solid that is formed when two liquids are mixed together and the solid does not dissolve.

May be one of the most common signs of a chemical reaction taking place.

Precipitates should not be confused with suspensions, which are solutions that are homogeneous fluids with particles floating about in them. Example: when a soluble carbonate reacts with Barium, a Barium Carbonate precipitate can be observed.

Formation of a Precipitate

Which is an element?

Which is a compound

?

___ H

___O___NaCl___H2O___HCl___He

Let’s Practice