Classification Of Matter

Classificatio n of Matter

Elements • Elements are the simplest kind of matter and are substances that contain only one type of atom, although they may be bonded to each other in a myriad of ways. • Most basic type of substances (there are around 114 of them “discovered” so far) that have distinct physical and chemical properties. 111 have been named officially by the IUPAC. • Elements cannot be broken down chemically into new substances. • Most can combine (in a chemical reaction) to form more complex substances called compounds.

Compounds • Compounds are more complex substances that consist of elements bonded together. • CANNOT be broken down by physical means. • CAN be broken down chemically into simpler substances. • Elements are chemically combined in a specific, constant, predictable ratio. • When compounds are broken down, the pieces have completely different properties than the original compound.

Mixtures • Consist of two or more kinds of matter mixed together. • These substances can be separated by physical means. • Substances are NOT bonded together. • Percents composition can vary.

Mixtures

• There is no specific “recipe”, or formula, for any mixture of two or more substances, in other words, the percent compositions can vary. • The properties of a mixture usually reflect those of its component substances. • Ex. Mixtures containing water are wet, mixtures containing salt taste salty, mixtures containing something toxic are toxic, etc.

Types of Mixtures • Heterogeneous mixture is not mixed thoroughly and is uneven in composition. Example: Sand + Water • Homogenous mixture is one where the substances are thoroughly mixed and evenly distributed. Examples: Air, Aqueous Solutions, Alloys.

Examples of Solutions • • • • • • • •

Homogeneous mixture Mixed molecule by molecule Can occur between any state of matter Solid in liquid - Kool-aid Liquid in liquid- antifreeze Gas in gas - air Solid in solid - brass Liquid in gas- water vapor

Solutions • Like all mixtures, they keep the properties of the components. • Can be separated by physical means

Compound vs. Mixture Compound

Mixture

One kind of pieceMolecules

More than one kind Molecule or atoms

Making is a chemical change

Making is a physical change

Only one kind

Variable composition

Which is it?

Element Mixture Compound

Separation of Mixtures Goal: Suppose you were given a mixture containing common table salt, sand, iron filings and sesame seeds. Describe and explain a procedure that would allow you to separate each of the four components.

Separation of Mixtures 1. Would the order of separation matter? 2. What physical properties of matter did you utilize in your procedure? 3. How would the individual masses of the components relate to the total mass of your original sample?

What is it?

What is it?

What is it?

What is it?

What is it?

What is it?

Lecture Quiz! Fill in the missing phase descriptions and phase change names.

? boiling

Gas: No definite shape or volume condensing ?

Liquid: Definite volume but not?shape

? deposition

subliming ? ? freezing melting ?

Solid: Definite volume and ? shape

Matter: Anything that has mass and volume