General Chemistry 1

what is chemistry

the study of matter and the changes it under goes

matter

Any thing that occupies space and has space

matter can be separated by physical methods as

pure substance - mixture

pure substance is

Has a definite composition and distinct properties

mixture

A combination of two or more substances in which the substances retain their distinct identities

pure substance can be separated by chemical methods as

element - compound

an element cannot be

separated into simpler substances by chemical means

A Compound is composed of

two different elements or more chemically united in fixed proportions.

A mixture is

heterogeneous or homogeneous combination of two or more substances that retain their individual properties.

An element can be

Atoms - Molecules

A Molecule is

Diatomic of two atoms or Polyatomic of more then two atoms bonded together.

A compound

Molecules containing different two atoms or more

reactivity / flammability is one of the

chemical properties of matter

color/mass/size

is one of the Physical properties of Matter.

the measurable properties of matter can be split as

Extensive - Intensive

Extensive propertied of matter

depends on how much matter is being considered

Intensive properties Does

not depend on how much matter is being considered

Weight is

the force that gravity exerts on an object

Volume is

the amount of space occupied by a sample of matter.

Density is

defined as the mass per unit volume.

density

= mass/volume

g/cm3 is the volume unit for

Solids

g/ml is the volume unit for

Liquids

g/L is the volume unit for

gases

to convert C to K

T(in Kelvin) = T(in Celsius) + 273.15

273 K = ? in C

= 0 C

100 C in K is

373 K

0 c in F =

32 F

100 c in F

= 212 F

Precision is

how close a set of measurements are to each other (reproducibility).

Accuracy

how close your measurements are to the true value.

Any digit that is not zero is significant

True

Zeros between nonzero digits are significant

True

Zeros to the left of the first nonzero digit are not significant

true

1.234 has

4 significant figures

606m has

3 significant figures

0.08 L

3 significant figures

2.0 mg

2 significant figures

0.00420 g

3 significant figures