Miscellaneous
What are the units for atomic mass?
amu (atomic mass units)
Define isotope.
Atoms that are the same element but different mass.
What formula can you use to find the average atomic mass of all isotopes?
(mass x %) + (mass x %)...
Where are electrons located in an atom?
Outside the nucleus in the electron cloud
Which subatomic particle(s) are found in the nucleus of the atom?
Protons and neutrons
Name 2 ways that isotopes are different from each other.
Number of neutrons & mass number
Carbon-12 has an abundance of 98.9% and C-13 has an abundance of 1.1%. What is the average atomic mass of Carbon?
Around 12.011 amu (atomic mass units)
Define average atomic mass.
The weighted average of all of the isotope masses multiplied by the relative abundance of each isotope.
Name 3 things that isotopes have in common.
Element, number of protons, atomic number.
How many protons are in an atom with -1 overall charge and 3 electrons?
2 protons
How many neutrons are in Potassium-40? (K-40?)
21
How many neutrons are in C-12, C-13, and C-14, respectively?
6, 7, and 8
What was the name of Rutherford's experiment that discovered the nucleus?
Gold Foil Experiment
How many neutrons are in an atom with 12 electrons, neutral charge, and a mass number of 24?
12
Will the average atomic mass of Carbon be closest to the mass of Carbon-12, C-13, or C-14? Explain how you know.
C-12: 99% abundant
C-13: 1% abundant
C-14: <1% abundnant
The mass will be closest to the mass of c-12 (12) because C-12 has the highest relative abundance.
Oxygen-16 has an abundance of 99.76% in the atmosphere and Oxygen-18 has an abundance of 0.201%. Would you expect the average atomic mass of Oxygen to be closer to 16amu or 18amu? Why?
Because 99.76% of the Oxygen in the atmosphere is Oxygen-16, I would expect the average atomic mass to be closer to 16 amu.
Which scientist discovered neutrons?
Chadwick