conservation laws classifying matter periodic tablepre-ap fixed

Matter – anything that has mass and takes up space.

Element – a substance that cannot be changed into simpler substances under normal laboratory circumstances.

Compound – a substance that can be separated into simpler substances only by chemical reactions.

Mixture – a physical blend of two or more substances that are not chemically combined.

Example

Element Examples

Compounds

What is Pure?

Pure – made of only 1 thing: 1 element or 1 compound (Ex. Cu, H2O)Pure substances contain elements or compounds with exactly the same composition Ex. Pure water = only H2O. The pure compound water

can be chemically broken down into the elements hydrogen & oxygen through a chemical reaction.

Chemicals used in lab are made to have a certain purity. Ex. 99% pure. However, they are treated as pure substances in this class.

Mixtures – 2 or more types of matter NOT chemically combined (physically combined).Mixtures can be separated physically (Ex filtering).

Heterogeneous – a mixture that is not uniform in composition. Example – a salad, chocolate chip cookies

Homogeneous – a mixture that has completely uniform composition. Example – salt water, pop (soda), soap

What Type of Substance?

• Dirt

• Vinegar

• Lucky Charms

• Air

• Chromium

• Sugar

• Neon

• Apple Juice

• Heterogeneous

• Homogeneous

• Heterogeneous

• Homogeneous

• Element

• Compound

• Element

• Homogeneous

Elements &The Periodic Table:

• Elements are the simplest pure substances. They are organized on the Periodic Table.– Groups/Families are vertical columns (#s 1-

18). Column 18 ( last column), contains unreactive Noble Gases.

– Periods are horizontal rows (1-7). Elements in the same group/family have similar properties (behave the same way).

The Periodic Table

The left side of the Periodic Table contains the metals. The right side contains the nonmetals. In between (on the “stairstep line”) are metalloids.

o Metals are shiny/have luster, conduct heat & electricity, are malleable (made into sheets), & ductile (made into wires).

o Nonmetals are poor conductors of heat & electricity. They may be gases at room temperature & tend to be brittle.

o Metalloids have some properties of metals & some properties of nonmetals. Often they are semiconductors (partly conduct electricity).

Different Types of Elements

Element Song

• Element song

Conservation Laws

Matter cannot be created nor destroyed (Law of Conservation of Matter). The total mass of reactants = the total mass of

products in a chemical reaction.

When physical & chemical changes happen, energy is also involved. Energy can be absorbed or released—but overall the

total energy of the system always stays the same (Law of Conservation of Energy).

What is the only letter not on the periodic table?

J