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Average Atomic Mass
History of Atomic Structure
Isotopes
Ions
Ions, Isotopes and Atomic Structure
100

K-39 (93.3%) and K-41 (6.7%) are two naturally occurring of Potassium. If you determined the average atomic mass, which mass number would the average atomic mass be closest to?

39

100
Which scientist came up with the idea of atoms, from the greek work atoma ?
Democritus
100
What is an isotope?
A form of an element that has the same number of protons but a different number of neutrons.
100
What is an ion?
An ion is a form of an element with a charge due to a different number of electrons.
100
What is the majority of the volume in an atom?
Empty Space
200
Why can we not use a "normal average" when calculating the average atomic mass of an element?
Because it does not take into account the abundance of each isotope.
200
Which scientist came up with 5 rules on how atoms behave, such as “atoms cannot be created nor destroyed in a chemical reaction”
Dalton
200
How many Neutrons does Sulfur 36 contain?
20 neutrons
200
How can you determine the charge of an atom?
Protons - electrons
200
Phosphorous 31 has a -3 charge. How many protons does it contain?
15
300

Calculate the average atomic mass of sulfur if 95.00% of all sulfur atoms have a mass of 32 amu, 0.76% have a mass of 33 amu, and 4.22% have a mass of 34 amu.

32.0856

300
Which scientist came up with the idea that there is a central nucleus where all the positive charge is located? (Gold Foil Experiment)
Rutherford
300
How many neutrons does Os-187 contain?
111 neutrons
300

An atom has 7 protons and 10 electrons. What is it and what is its charge?

Nitrogen; -3 charge

300
How many electrons does Carbon have in its nucleus?
0------ NO Electrons in the NUCLEUS!!!!!!!!!!!
400

The element copper has naturally occurring isotopes of 63-Cu and 65-Cu. The relative abundance and atomic masses are 69.2% for a mass of 63amu and 30.8% for a mass of 65 amu. Calculate the average atomic mass of copper.

63.616

400
Which scientist discovered the electron and came up with a model of the atom known as the “plum pudding model”. He used the Cathode Ray to discover the electron.
J.J. Thomson
400

An atom is found to have 6 protons and 8 neutrons. What is it's chemical symbol, mass number and atomic number.

Carbon 6=atomic number 14= mass number

400
An atom has a charge of -2. It has 16 protons. How many electrons must it have? Also what element is it?
Sulfur-18
400
Can an isotope be an ion?
Yes, all atoms are isotopes. Ions are simply charged atoms.
500
There are three isotopes of silicon. They have mass numbers of 28, 29, and 30. The average atomic mass of silicon is 28.086amu. Which isotope is most abundant?
Si-28
500

Who created the model of the atom with specific energy levels that the electrons travel on?

Bohr

500
An atom is found. It has 53 protons. Using the average atomic mass, how many neutrons does the most common isotope most likely have?
74
500
A chlorine atom has 18 electrons. What charge must it have?
-1
500
An atom has 36 electrons, a mass number of 80 and a -1 charge. How many neutrons does it have?
45