What is chemistry????

Chemistry- the science that investigates and explains the structure and properties of matterMatter is anything that has mass and

volume.

Mass is the amount of matterVolume is the amount of space an object

occupies. MASS WEIGHT

Mass WeightConstant Varies dependent on

gravityMeasured on a balance Measured on a scale

LAW OF CONSERVATION OF MASS (Lavoisier)- Matter (Mass) can not be created nor destroyed; just changed/transformed.

Matter exists in 6 phases.Bose-Einstein CondensateSolid*Liquid*

Aqueous* (dissolved in water)Gas*PlasmaNeutron star

Can this law be broken????

E = MC2

A solid is matter with a fixed volume and shape that does not change much with temperature. Atoms and molecules are held tightly in a rigid structure.

A liquid has a fixed volume but NOT a fixed shape. It conforms to the shape of the container. Its volume changes somewhat with changes in temperature. The particles in a liquid are not held together in a rigid manner; they can slip past one another.

A gas has neither a fixed shape nor fixed volume. It expands to fill its container completely; its volume is very sensitive to temperature and pressure. A gas’ particles are not held to one another

Matter can be characterized according to its properties (characteristics), which can be either physical or chemical.

Physical properties can be measured and observed without changing the substance.

Examples: color, texture, shape, odor, phase, length, mass

Chemical properties are properties that are measured when a substance interacts when in contact with other materials

Examples: flammability, reactivity

When we examine matter we make observations.

Observation vs. Inference

An observation is made using your senses. (sight, hearing, touch, etc.) You gather facts about something.

An inference is similar to a conclusion. It is a prediction.

Example: When piece of paper burns, it releases a visible gas. The gas is smoke, a mixture of carbon dioxide and water.

Observation Inferen

ce

Observations can be of two types:

Qualitative and Quantitative

A quantitative observation is one that involves numerical data.

(quantity means amount = number) 

A qualitative observation does not.

Chemistry involves both qualitative and quantitative observations. 

Quantitative observations are more exact than qualitative.

We will focus on quantitative observations.

Classify the following as either quantitative or qualitative observations.

My eyes are brown

The most popular color for a new car in 2000 was silver 

My neck size is 17 inches

My average grade last year was 84% 

Physics is a difficult subject