Atomic Theory, Subatomic, Ions, Isotopes, Avg Atomic Mass

Order of Evolution of Atomic Model

Aristotle, Dalton, Thomson, Rutherford, Bohr, Chadwick

Aristotle idea of atom

made of fire, water, air, earth

Dalton atomic theory

proposed atomic theory based on experimentation, observation, evidence.

Dalton Model of Atom

Neutrally charged sphere, completely filled

atomic theory

(1) All matter is composed of atoms

(2) Atoms of a given element are identical

(3) Atoms of different elements are different

(4) Atoms combined separate and rearrange in chemical reactions

Atoms combine in simple whole number ratios

Thomson Atomic Theory

discovered the electron via ray experiment, oil drop experiment, double split experiment

Thomson model of the atom

Plum pudding model

Rutherford atomic theory

discovered the atomic nucleus and its concentrated positive charge conducted the goil foil experiment

Rutherford atomic model

Nucleus in the center with a positive charge with floating electrons around

Bohr atomic theory

Electrons orbit the nucleus

Bohr Model

electrons in circular orbits around the positive nucleus

Chadwick atomic theory

discovered neutrons

atomic number

number of protons

mass number

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

Nuclide symbol

mass number on top, atomic number on bottom

Nuclide name

name- atomic mass

Ion

loses or gains electron, creates charge

Isotopes

Atoms of the same element with different numbers of neutrons, changes mass

Cation

positively charged ion- gives away electron, positivity charged (metals)

Anion

A negatively charged ion-gains electron, negatively charged (non metals)

Change to -ide

gained electrons, non metals.

average atomic mass

the weighted average of the masses of all naturally occurring isotopes of an element

abundance of isotopes

Percentage of each isotope weight

calculating atomic mass

multiply each atomic mass by the percent abundance add them up Divide by 100 or move two decimal spaces in percent