CheMASTERY

Question 0

JJ Thomson

Answer 0

Proved Crookes’ negative “beam” was really particles called “electrons”
Realized electrons were smeller than atoms
Plum Pudding Model
Cathode Ray Tube

Question 1

John Dalton

Answer 1

aka “the marble guy”
Atoms are all solid w/ uniform density
Atoms are the smallest particles of nature
All atoms of the same element are identical
*Atoms of diff. sizes can combine to form compounds

Question 2

Ernest Rutherford

Answer 2

Discovered that atoms had a "nucleus"
Gold Foil Exp.
   Dense,+charged nucleus
   Atom is mostly empty space
   Electrons roam freely around the nucleus

Question 3

Neils Bohr

Answer 3

Supported Rutherford’s model, but explained its weakness
Electrons are in certain shells/orbits at specific distances from the nucleus
Planetary Model

Question 4

Ewin Schrodinger

Answer 4

Wave mechanical model
Mathematically describes the probability of finding an electron in an “electron cloud”
Regions where you can find electrons are orbitals
Orbitals have diff. energy levels

Question 5

3 subatomic particles w/ charges & locations

Answer 5

Protons (+) inside nucleus
Neutrons (neutral) inside nucleus
Electrons (-) outside nucleus

Question 6

How do atoms become +/- ions?

Answer 6

+…lose electrons
-…gain electrons
(From P)

Question 7

Why are the atomic masses on the periodic tale NOT whole #s?

Answer 7

B/ the atomic mass is an average of all the isotopes

Question 8

Average atomic mass formula

Answer 8

(Mass)(% abundance in decimal form)

[2 decimal places left]

Question 9

% abundance formula

Answer 9

each type of marshmallow / total in bag x 100%

Question 10

Isotope

Answer 10

Atoms of the same element w/ diff. # of neutrons, therefore diff. masses

Question 11

Isotope notation

Answer 11

H-1 (1)=atomic mass
H-2
H-3

Question 12

Nuclear symbol

Answer 12

Atomic mass +/-

Atomic # Letter

Question 13

Ion

Answer 13

Charged particle

Between protons & electrons!

Question 14

Responsible for the identity of the element?

Answer 14

Protons

Question 15

Responsible for the mass of the atom?

Answer 15

Protons & neutrons

Question 16

P=?

Answer 16

Atomic# & #E (if neutral)

Question 17

E=?

Answer 17

Atomic#

Question 18

N=?

Answer 18

Mass#-Atomic# (P)

Question 19

Mass#=?

Answer 19

P+#N

Question 20

Isotopic notation

Answer 20

...
H-1
H-2  
H-3
...
"2" atomic mass

Question 21

Nuclear symbol

Answer 21

Mass      12
--------         C
Atomic#   6
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
               13 
                    C
                6
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
               14
                    C
                6