CHEM 109 EXAM 1 - DRAKE WKU

Scientific Method

Series of steps to solve scientific problems including observation, experimentation, and hypothesis testing

Law

1 or more hypotheses that describe scientific events

Theory

A hypothesis that has been repeatedly experimented upon with the same results

Chemistry

Study of matter composition, properties, and transformation

Matter

Anything with mass that takes up volume

Solid

Definite shape, volume, close together particles

Liquid

Definite volume, take shape of whatever container they are in

Gas

No definite shape or volume, will fill volume and take shape of container, far apart particles

Physical Change

can be observed without changes to material composition

Chemical Change

changes that convert one substance to another

Substance

Has fixed composition, cannot be changed physically ex. H2O

Mixture

Multiple substances with physical separation and varying composition

Solutions

Mixtures with solid particles suspended in a liquid

Colloids

Heterogeneous mixtures with suspended particles

Mass

The amount of matter in an object

Weight

force that matter feels due to gravity

Equation for density

D = M/V

Specific Gravity

compares the density of a substance to the density of water

Equation for Specific Gravity

Density of substance/1

Metals

Left side of table, shiny solids, good conductors, solid at room temp (except mercury)

Nonmetals

Right side of table, not shiny, poor conductors, solid, liquid, or gas at room temp

Metalloids

Located on the solid, stair shaped line on table, have properties of metals and nonmetals

Compound

A substance made up of 2+ elements put together

Dalton

Stated matter consists of atoms, atoms are indestructible, elements classified by atomic weight, the reactions of elements are their atoms interacting

JJ Thomson

Discovered electron, plum pudding model

Ernest Rutherford

Discovered the nucleus through the gold foil experiment, electrons in orbit around nucleus

Niels Bohr

stated electrons have fixed orbit, low energy = low orbit, first idea of electron shells

Erwin Schrödinger

Produced the first equation to predict where electrons are most likely to be around nucleus

Atomic Number

the number of protons in the nucleus of an atom, = to the number of electrons

Mass number

Sum of neutrons and protons (particles with mass)

Isotope

When an atom has the same number of protons as an element, but not electrons

Atomic weight

Avg. of all isotope weight of an element

Alkali metals

Group 1a, shiny, soft, low melting point, good conductors, react with water

Alkaline metals

Group 2a, same properties as alkali but less reactive

Halogens

group 7a, very reactive nonmetals

Noble gases

group 8a, very stable, only form compounds under extreme duress

Electron sub-shells

s - 2e, p - 6e, d - 10e, f - 14e

Valence electrons

Electrons in the outermost energy level. the max # is 8

Atomic Radius

size of an atom, increases down a column and to the left of a row

Ionization Energy

Energy needed to remove electrons, increases up a column and to the right of a row

Most abundant isotope

is the one with the closest atomic mass to the one on the periodic table