Its Not Rocket Science: Chemistry- Unit 3: Electrons

Electron

a negatively charged subatomic particle

electromagnetic radiation

a form of energy that exhibits wavelike behavior as it travels through space

Wavelength

The distance between two corresponding parts of a wave

Frequency

the number of complete wavelengths that pass a point in a given time

emission spectrum

the spectrum of light released from excited atoms of an element

Heisenberg uncertainty principle

states that it is impossible to determine simultaneously both the position and velocity of an electron or any other particle

valence electrons

The electrons in the outermost shell of an atom; these are the electrons involved in forming bonds.

octet rule

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

Ions

positively and negatively charged atoms

Lewis structure

A model that uses electron-dot structures to show how electrons are arranged in molecules. Pairs of dots or lines represent bonding pairs.

quantum theory

the study of the structure and behavior of the atom and of subatomic particles from the view that all energy comes in tiny, indivisible bundles

Electron Orbital

the three-dimensional space where an electron is found 90% of the time

electron configuration

the arrangement of electrons in an atom

Periodic Trends

property of the elements that can be predicted from the arrangement of the periodic table

Coulomb's Law

The relationship among electrical force, charges, and distance: The electrical force between two charges varies directly as the product of the charges and inversely as the square of the distance between them.

atomic radius trend

increases down a group, decreases across a period

atomic radius

one-half the distance between the nuclei of two atoms of the same element when the atoms are joined

Reactivity

The ease and speed with which an element combines, or reacts, with other elements and compounds.

reactivity trend

Most reactive corners are Francium and Flourine: noble gases not included

shielding effect

the electrons of previous energy levels sheilds the pull of the nucleus on outer level electrons (increases going down and constant going across)

Electronegativity

A measure of the ability of an atom in a chemical compound to attract electrons

electronegativity trend

increases across a period, decreases down a group

ionization energy

The amount of energy required to remove an electron from an atom

ionization energy trend

decreases from top to bottom in a group; increases from left to right in a period

oxidation number

Positive or negative number that indicates how many electrons an atom has gained, lost, or shared to become stable

ionic radius

Distance from the center of an ion's nucleus to its outermost electron

Ionic Radius Trend

increases down a group, decreases across a period