Atomic Model Theory

Question 1

identify the parts of a symbolic representation of an element

Answer 1

A= mass number
Z = atomic number
X = element symbol

Question 2

atoms of the same element having different masses

Answer 2

Isotopes

Question 3

Weighted average of the masses of all the isotopes

Answer 3

Atomic mass

Question 4

Formula for determining the atomic mass

Answer 4

(percentage of the element / 100 ) (mass number)

Question 5

john daltons atomic theory

Answer 5

• All matters consists of atoms
• atom cannot be created, divided or destroyed or converted
• atoms of particular element are identical properties
• atoms of different elements are different properties
• atoms of different elements combine in whole number ratios to produce compounds (stable)
• chemical change involves joining, separating, or rearranging atoms

Question 6

john Dalton’s model and weakness

Answer 6

Solid sphere model

recognized atom: indivisible, identical, and compounds are different types of atoms

atoms aren’t indivisible- they have subatomic particles

Question 7

J.J. Thomson

Answer 7

Plum pudding model
discover of electrons - corpuscles

no nucleus and didn’t explain later exp observations

Question 8

ernest rutherford

Answer 8

nuclear model
positive charge is in the nucleus of an atom

didnt explain the electrons remaining in orbit around the nucleus

Question 9

Neils bohr

Answer 9

planetary model

• electron orbits and emission of spectra of some elements

moving electrons should emit energy and come back to the nucleus and the model was unapplicable for heavier atoms

Question 10

Erwin Schrodinger

Answer 10

Electrons are not in a set path = clouds of probability

electrons are not in orbits but have an area where we are likely to find them

still accepted as the most accurate model

Question 11

Cathode ray tube exp

Answer 11

JJ Thomson - stream of negative particles of energy - discovered electrons

Question 12

Oil drop experiment

Answer 12

Robert millikan - magnitude ofmass and charge of electron

Question 13

Gold foil experiment

Answer 13

Ernest Rutherford - alpha particles - positive charges deflected the particles - discovery of nucleus and protos

Question 14

Bombarded beryllium with alpha particles

Answer 14

James Chadwick - uncharged particles has same mass as neutrons

Question 15

Emission spectrum

Answer 15

Liht is produces when excided
Wuantization energy
excitd state
relaxation

Neils bohr

Question 16

Quantum mechanical atomic model

Answer 16

Erwin scrodinger
wave aprticle duality
probability of finding electrons within th eprincipal energy model (atomic orbital)