CHAPTER 1

5:

CLASSIFI

CATIO

N OF

MATTE

R

COMPOSITION OF MATTER

Matter can exist as:

• Substance: Type of matter with a fixed composition; can be element or compound; Ex: He, water, salt

• Element: Substance made up of atoms that are all alike; cannot be broken down into any other substance

Ex: graphite in pencil point

• Compound: Substance in which the atoms of 2 or more elements are chemically combined in a fixed proportion

Ex: water, CO2

• Mixture: Matter composed of two or more substances that can be separated by physical means

MIXTURES

Heterogeneous Mixture: Mixture in which different materials remain distinct

Ex: Salad, oil and vinegar dressing

• Suspension: A heterogeneous mixture made of a liquid and solid particles that settle

Ex: River deltas, seasoning in salad dressing

• Colloids: A heterogeneous mixture with particles that never settle

Ex: milk (water, fats, proteins), fog (liquid suspended in air)

Note: you can identify a colloid by shining a light through it; light beam is invisible as it passes through a solution, but it can be seen as it passes through a colloid; This scattering of light

through a colloid is called the Tyndall Effect

MIXTURES

Homogeneous Mixture: A mixture that remains constantly and uniformly mixed and has particles that are so small that they cannot be seen with a microscope; solution is same thing as a solution

Ex: tea, vinegar

PROPERTIES OF MATTER: PHYSICAL

Physical Property: Any characteristic that you can observe without changing the identity of a substance

Ex: color, shape, size, density, melting point, boiling point, viscosity, solubility, malleability, conductivity, melting point, boiling point, solubility

Distillation: Process of separating substances in a mixture by evaporating a liquid and recondensing its vapor

Ex: separate 2 liquids with different boiling points

PROPERTIES OF MATTER: CHEMICAL

Chemical Property: Any characteristic of a material that you can observe that produces one or more new substances,;describe the ability of a substance to change into another substance

Ex: flammability and reactivity

PHYSICAL AND CHEMICAL CHANGES

PHYSICAL CHANGES IN MATTER

• Physical changes only change physical properties of a substance

• Does not produce a new substance

• Phase changes are physical

Ex: breaking, bending, melting, freezing, tearing, dissolving

PHYSICAL AND CHEMICAL CHANGES

CHEMICAL CHANGES IN MATTER

• The process by which a substance changes into another substance Does not produce a new substance

• Also called chemical reactions

• Ex: Burning, rusting, baking soda and vinegar

Law of Conservation of Mass:

total mass of the reactants = total mass of the products