Atom Scientists
Who was the first scientist to believe in such things as atoms?
Democritus
Name the three subatomic particles
Formula for finding Atomic Mass
Total Mass/Total # of Atoms
or
(Mass# x %) + (Mass# x %) +... /100
What is the charge of an electron
-1
What is a quark
small particles which make up protons and neutrons
John Dalton
What subatomic particle is used to determine Atomic # of an element
# of Protons
Atomic mass on the periodic table is a decimal because it is an ___________ of all isotopes for an element
average
What is the mass of electrons
0 amu
What is the mass of a quark
1/3 amu
Match the Scientist to their work
Incorrectly Believed that atoms were filled with positive pudding-like material
Discovered that most of the atom is empty space
Calculated how small the mass of electrons was
Rutherford
Thomson
Millikan
Rutherford - Discovered that most of the atom is empty space
Thomson - Incorrectly believed that atoms were filled with positive pudding-like material
Millikan - Calculated how small the mass of electrons was
Which two subatomic particles are in the nucleus and make up the mass # of an element
Protons and Neutrons
In a sample of an element, 20 atoms each had a mass of 10amu and 80 atoms each had a mass of 11 amu. What is the average atomic mass of the element
10.8amu
(20x10amu) + (80x110amu)/100 = 1080/100 = 10.8amu
What is the charge of a nitrogen atom with 9 electrons
-2
What force hold together the nucleus
Strong force
Match the Model to the Scientist
Democritus - John Dalton - J.J. Thomson - Millikan - Rutherford - Bohr
Planet Model - Plum Pudding Model - No Model; Just logic and reasoning - Nuclear Model - Billiard Ball Model - Oil Drop Experiment
Democritus - No Model
John Dalton - Billiard Ball
J.J. Thomson - Plum Pudding
Robert Millikan - Oil Drop
Ernst Rutherford - Nuclear Model
Niels Bohr - Planet Model
There is a Carbon atom with an a mass # of 12, and a carbon atom with a mass # of 14. These would be ________ of each other?
Isomers
The atomic masses of two naturally occurring isotopes of an element are 10 amu and 11 amu. If the element exists as 80% isotope-10 and 20% isotope-11, what is its average atomic mass?
10.2 amu
(10x80) + (11x20)/100
What is the max number of electrons each level can hold
Level 1
Level 2
Level 3
Level 1 - 2
Level 2 - 8
Level 3 - 18
What force causes radioactive decay
Weak Force
For each scientist, list what he discovered about atoms that is still true today and which ones are incorrect about his model of the atom
Democritus
Dalton
Bohr
- All matter is made of atoms
- Atoms solid like billiard ball
- Electrons have energy levels
- Atoms are smallest particle
- Atoms react in whole # ratios
- Atoms of different elements are different
- Electrons circle nucleus like planet
- Same elements are exactly alike
Democritus:
True - All matter made of atoms
False - Atoms are smallest particle
Dalton:
True - Atoms react in whole # ratios + Atoms of different elements are different
False - Atoms solid like billiard ball + same elements are exactly alike
Bohr:
True - Electrons have energy levels
False - Electrons circle nucleus like planet
Give me the location, charge, mass, and what they determine (atomic #, mass etc.) of all 3 subatomic particles
Protons - In nucleus, +1 charge, 1 amu, determine the atomic # of an element, and also help determine mass # with protons
Neutrons - In nucleus, neutral charge, 1 amu, also help determine mass # with protons
Electrons - In electron cloud outside of the nucleus, -1 charge, 0 amu
An element has two isotopes: one has a mass of 24 amu and makes up 75% of the element, while the other has a mass of 26 amu and makes up 25%. What is the element's average atomic mass?
24.5amu
(24x75) + (26x25)/100 = 24.5amu
Draw a Bohr Diagram of Chlorine and Magnesium
Chlorine - 17 protons 18 neutrons - 2 in level 1 - 8 in level 2 - 7 in level 3
Magnesium - 12 Protons 12 neutrons - 2 in level 1 - 8 level 2 - 2 level 3
What is the smallest force in an atom
Gravity