Atomic Structure

Model of an atom that shows electrons in circular orbits around the nucleus

Greek philosopher that said all matter is made of tiny particles called "atomos" or atoms

all matter is made up of individual particles called atoms, which cannot be divided

Discovered the electron, plum pudding model

Gold foil experiment, discovered nucleus

Alpha-particles were directed at a thin sheet of gold foil; most passed through the foil, but a few were deflected; this led to the discovery of the atomic nucleus.

1913- discovered that electrons move around the nucleus in orbits called electron shells.

An experiment that showed that electrons had mass and a charge

Electron cloud model
Electrons travel in waves; it's impossible to know where an electron is at any given time

The average mass of all the isotopes of an element

The sum of the number of neutrons and protons in an atomic nucleus

Atoms of the same element that have *different numbers of neutrons*

Positively and negatively charged atoms

States that atoms lose, gain or share electrons in order to acquire a full set of *eight * valence electrons

mass/volume

A combination of two or more substances that are not chemically combined

A *homogeneous* mixture of two or more metals

Contain information regarding first aid, the manufacturer, and proper personal protection equipment for use.

The amount of a chemical that kills 50% of the animals in a test population; median lethal dose to kill 1/2 of a population

Threshold limit value, level a worker can be exposed to per shift w/o hazardous effects

Permissible exposure limit max amount a worker can be exposed to under OSHA regulations

Personal protective equipment worn to minimize exposure to hazards that cause injuries and illnesses

Inhalation, skin contact, swallowing

the ability of a chemical to cause harm to an organism with only one exposure

adverse effects that occur after a long period of low-level exposure to a toxicant

Exist as pairs in their elemental form o-o symbol