1.1 The Puzzle of Matter

• Objectives– Classify matter according

to its composition.– Distinguish between

elements, compounds, homogeneous mixtures, and heterogeneous mixtures.

– Relate the properties of matter to structure.

Chemistry

• Textbook Definition the science that investigates and explains the structure and properties of matter.

– Macroscopic level of matter—based on behavior and observed composition of matter

– Submicroscopic level of matter—used to determine how the hidden structure of matter influences its behavior

Matter

Definition: is anything that takes up space and has mass.

Examples:

Non examples:

Matter can be classified as a…

• A Pure Substance– matter with the same

fixed composition and properties.

– Pure means that every bit of the matter being examined is the same substance.

– Examples:

• Mixture– is a combination of two

or more substances in which the basic identity of each substance is not changed.

– Can be separated by physical processes (aka physical changes)

– Examples:

Pure Substance vs. Mixture

Mixtures can be classified as..

• Heterogeneous: does not have a uniform composition and its individual substances remain distinct.

• Homogeneous: always has a uniform composition and is the same throughout.

• Can be liquid or solid• Alloys: solid solution

that contains different metals and sometimes nonmetallic substances.

• AKA: solutions

Heterogeneous vs. Homogeneous

Solutions

• Made up of:– The solute is the substance being dissolved.– The solvent is the substance that dissolves the

solute.– When the solvent is water, the solution is called

an aqueous solution.

Pure Substances can be classified as….

• Elements– An element is the simplest

form of matter– There are 117 elements—

only 90 occur naturally on Earth.

– The periodic table organizes elements and uses chemical symbols that are universally understood.

– Represented by: Chemical Symbol

• Compounds– A compound is a chemical

combination of two or more different elements joined together in a fixed proportion

– Represented by chemical formula-show what elements make up a compound and the number of atoms of each element.

– Molecule- smallest unit of a compound

Element vs. Compound vs. MoleculeZn

H2O

S

SO2