Units 1 and 2: Measurements, Properties, and Mass

Precision

The degree to which repeated measurements are made to each other

Accuracy

Making measurements that are as close as possible to the "accepted value"

Matter

Anything that has mass and takes up space

Pure Substance

A substance that cannot be separated by physical characteristics

Mixture

A substance that can be separated by physical characteristics

Element

A pure substance that consists of only one kind of atom

Compound

A pure substance that contains two or more elements that are chemically combined in a fixed ratio

Heterogeneous

Two or more materials in distinct regions called phases

Homogeneous

Two or more materials in one phase - the same throughout

Physical Properties of Separating Mixtures

Color, size, density, shape

Processes of Separating Mixtures

Distillation, chromatography, decantation, filtration

Physical Property

Any property of matter that can be observed or measured without altering its chemical composition

Physical Property Examples

Color, shape, size, density, malleability, conductivity, ductility

Chemical Property

Properties that describe how matter acts in the presence of other materials, or how it changes composition

Chemical Property Examples

Reactivity, toxicity, flammability, combustibility

Physical Change

Any change in any physical property

Chemical Change

A change to the chemical identity of a substance

Atom

The smallest particle of an eleemtn and is capable of chemical interactions

Nucleus

The part of an atom that contains protons and neutrons (subatomic particles)

Electron Cloud

The part of an atom outside the nucleus that contains the electrons

Monatomic

When an atom occurs in nature by itself

Diatomic

When an atom occurs in nature in bonds with two atoms

Polytomic

Many atoms bonded together to form a larger molecule

Three common states of matter

Solids, Liquids, and Gases

Kinetic Molecular Theory

1) All matter is composed of particles that have a certain amount of energy. 2) These particles are in constant motion, dictated by the amount of energy in that matter. 3) There are spaces between particles and forces between particles as they get closer to each other. 4) The more mass the particles have, the slower they move (with the same amount of energy)

Melting

Solid to Liquid

Freezing

Liquid to solid

Evaporation

Liquid to gas

Sublimation

Solid to gas

Deposition

Gas to solid

Condensation

Gas to liquid

Question

What you're looking to solve

Beginning Ideas

Fill in the gaps of background information

Hypothesis

An educated guess that needs to include: what will happen, and why will it happen?

Independant Variable

Changing for effects

Dependant Variable

Changing as a result of the dependent

Constant

A value that does not change

Qualitative Data

Observations

Quantitative Data

Data (specifically in a table)

Claim

Most important; what did you learn from your data? What does the data tell you?

Evidence

What data did you use to come up with the claim? Averages often show this (change: final minus start)

Scientific Explanation

A researched, proven explanation of why you got the results you did

Bibliography

Where you got your info (just a link is fine)