Download What is chemistry????

Chemistry- the science that
investigates and explains the
structure and properties of matter
 Matter is anything that has mass and volume.
 Mass is the amount of matter
 Volume is the amount of space an object occupies.
MASS  WEIGHT
Mass
Weight
Constant
Measured on a balance
Varies dependent on gravity
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 Condensate
 Solid*
 Liquid*

Aqueous* (dissolved in water)
 Gas*
 Plasma
 Neutron star
 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
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. Observation
The gas is smoke, a mixture of carbon dioxide and water. Inference
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