CHEMISTRY Q2 EXAM

Hypothesis

An if/then (and because) stated that poses a tentative explanation about what has been observed

Conclusion

judgment based on the information obtained

Quantitative

measured by the quantity of something

Qualitative

the type of observation that utilizes all 5 senses

Independent Variable

Variable you plan to change

Dependent Variable

the value that changes as a result of the IV

accuracy

refers to how close a measured value is to an accepted value

precision

refers to how close a series of measurements are to one another

Celsius to kelvin

K=\*C + 273

Kelvin to Celsius

C=\*K - 273

Solid

definite shape & volume

Liquid

Indefinite shape & definite volume

Gas

Indefinite shape & indefinite volume

Plasma

indefinite shape & volume and compressible

Vaporization

liquid changes into gas

Condensation

where gas changes into liquid

Evaporation

Liquid to gas

Boiling

liquid turns into vapor

melting

solid turns into a liquid

freezing

liquid turns into a solid

deposition

solid turns into gas

mixture

a combo of two or more pure substances & each pure substance retains its individual chemical properties

homogeneous mixture

composition is constant throughout

heterogeneous mixture

individual substances remain distinct

pure substances

elements & compounds

separating mixtures

filtration, distillation, crystallization, sublimation, chromatography

element

__cannot be separated__ into simpler substances physically and chemically

compound

made up of 2 or more elements combined and can be broken chemically

molecules

contains two or more atoms of the same type

tyndall effect

can see floating particles when light shines on liquid

colloids

a heterogeneous mixture

atomic number

number of protons and electrons

Democritus

philosopher: matter is composed of atoms that move through empty space. Properties of matter

Aristotle

Philosopher: empty space can not exist, matter is made of of earth, water, air, and fire

John Dalton

Scientist: matter is composed of indivisible atoms; atomic theory

J.J. Thompson

discovered the electron

Cathode Ray Experiment

experiment that discovered the electron?

Ernest Rutherford

discovered the positive charged nucleus

The Gold Foil experiment

experiment that discovered the positive charged nucleus

James Chadwick

discovered the neutron?

Cation

positive charged ion

Anions

negative charged ion

periods

horizontal

groups

vertical

group 1

alkali metals

group 2

alkali earth metals

group 3-12

transitional metals

group 13

boron group

group 14

carbon group

group 15

nitrogen group

group 16

oxygen group

group 17

halogen

group 18

noble gases

s-block

groups 1 & 2

d-block

groups 3-12

p-block

groups 13-18

f-block

lathemides & achinides

oxidation number

charge (neutral for atoms)

ionic compound

cation + anion (metal + non-metal)

mono-

1

di-

2

tri-

3

tetra-

4

penta-

5

hexa-

6

hepta-

7

octa-

8

nona-

9

deca-

10

covalent compound

anion + anion (non-metal + non-metal)