Atomic Structure
This subatomic particle has a positive charge and is found in the nucleus.
What is a proton?
This scientist discovered the electron using the cathode ray tube experiment.
Who is J. J. Thomson?
Atoms of the same element with different numbers of neutrons are called this.
What are isotopes?
The three types of radiation are alpha, beta, and this.
What is gamma radiation?
This is the spontaneous breakdown of an unstable atomic nucleus.
What is radioactive decay?
This is the number of protons in an atom’s nucleus.
What is the atomic number?
This scientist performed the gold foil experiment.
Who is Ernest Rutherford?
Oxygen-16 can be written in nuclear notation with this atomic number as a subscript.
What is 8?
This type of radiation can be stopped by paper or skin.
What is alpha radiation?
In alpha decay, the atomic number decreases by this amount.
What is 2?
This is the total number of protons and neutrons in an atom’s nucleus.
What is the mass number?
This scientist discovered the neutron.
Who is James Chadwick?
This is the weighted average of the masses of all naturally occurring isotopes of an element.
What is average atomic mass?
The symbol for a beta particle shows this number as the mass number.
What is zero?
This is the time required for half of a radioactive sample to decay.
What is half-life?
In Arsenic-75, this is what the number 75 represents.
What is the mass number?
This scientist determined the mass-to-charge ratio of the electron.
Who is Robert Millikan?
An atom of Bromine-80 has this many neutrons.
What is 45?
Unlike chemical reactions, nuclear reactions involve changes to this part of the atom.
What is the nucleus?
This is the conversion of one element into another through bombardment with high-energy particles.
What is artificial transmutation?
An atom of Magnesium-24 has this many neutrons.
What is 12?
According to Dalton’s atomic theory, atoms combine in these types of ratios to form compounds.
What are simple whole-number ratios?
If silicon has isotopes with masses 27.977 g (92.21%), 28.976 g (4.70%), and 29.974 g (3.09%), its average atomic mass is approximately this value.
What is 28.1 g (or 28.091 g)?
This is why gamma emission does not lead to transmutation.
What is it does not change the number of protons or neutrons; it only releases energy?
If Selenium-83 has a half-life of 25 minutes, this is how long it takes for a 10.0 mg sample to decay to 1.25 mg.
What is 75 minutes?