Honors Chemistry Unit 2

Physical change

Physical properties change, but chemical identity stays the same

Chemical Change

Original substance is converted into a new substance that has a different composition and new physical and chemical properties

Decanting

Solid / liquid, waiting for settling, different densities

Filtering

Solid / solid, different soluteabilities

Chromotography

Liquid / liquid, based on color differences

Magnetism

Solid / solid, iron nickel cobalt all magnetic

Distillation

Liquid / liquid, different boiling points

Centrifuge

Solid / liquid, small particulate, spins really fas, separate based on density differences

Atoms

Submicroscopic particles that are the fundamental building blocks of ordinary matter

Molecules

Atoms bind together in specific geometric arrangements to form molecules

Chemistry

The science that seeks to understand the behavior of matter by studying the behavior of atoms and molecules

Hypothesis

A tentative interpretation or explanation of the observations

Experiments

Highly controlled procedures designed to generate observations that confirm or refute a hypothesis

Scientific law

Brief statement that summarizes past observations and predicts future ones

Law of conservation of mass

In a chemical reaction matter is neither created nor destroyed

theory

A model for the way nature is and tries to explain not what nature does, but why

Atomic theory

Proposed that matter is composed of small and indestructible particles called Atoms

4 states of matter

Solid, liquid, gas, plasma

Amorphous

It’s atoms or molecules do not have any long organized order.

Pure substance

Made up of only one component

Mixture

Composed of two or more components in proportions that can vary from one sample to another

Element

Substances that cannot be chemically broken down into simpler substances

Compound

A substance composed of two or more fixed elements

Heterogeneous mixture

Composition varies from one mixture to another

Homogeneous mixture

One with the same composition throughout

Physical changes

Changes that alter only a state or appearance, but not composition

Chemical changes

Changes that alter the composition of matter

Physical property

Substance displays without changing its composition

Chemical property

Property that a substance displays only by changing its composition via a chemical change

Energy

The capacity to do work

Work

The action of a force through distance

Kinetic energy

Total energy is a sum of kinetic energy and potential energy, this is the energy of motion

Potential energy

Energy associated with its position or composition

Thermal energy

Energy associated with the temperature of an object

Law of conservation of energy

Energy is neither created nor destroyed

Crystalline

Repeating, orderly pattern