History of the Atom
Rutherford
Protons Neutrons and Electrons
Isotope Stability and Half Lives
Radiation
100
Matter is composed of very small particles. What do we call them? (!)
Atoms
100
Who is attributed with the discovery of the proton?
Ernest Rutherford
100
List the charges on Protons, Electrons and Neutrons respectively.
Positive, negative, neutral.
100
What is an isotope of an atom?
Another atom that differs only in the number of neutrons it has.
100
Compare the penetrance of alpha, beta and gamma? DOUBLE POINTS FOR DETAILS
Alpha is least then beta then gamma, DETAIL: Alpha about 10mm of air, Beta about 30cm air stopped by paper, Gamma, about 10cm lead or more, stopped by a lot of lead or a lot of concrete
200
The Blob was a model proposed by whom?
John Dalton
200
What did Rutherford expect to happen to to the alpha particles as they went through the gold foil?
Numerous small deflections
200
Uranium 235, 92 has how many protons?
92
200
What is a half life of a radioactive substance?
The time taken for half of the undecayed atoms to disintegrate
200
Name IN DETAIL the particle released in alpha, beta and gamma radiation.
Helium NUCLEUS, NUCLEAR electron, photon of light
300
Thomson came up with a model of the atom. What was it known as?
The Plum Pudding model
300
What did Rutherford observe when he shot alpha radiation through gold foil? (3 answers with percentages)
99.9% straight through, 0.09% minor deflections, 0.01% major deflections.
300
To find the number of electrons, you can look at the number of _________. This is the same as the ________ _______
Protons, Atomic Number
300
ANSWER A ONLY Nuclei with low numbers of nucleons are stable because they are held together by the _______A_________ force. Eventually the __________B___________ force takes over and the nuclei become less stable.
Strong Nuclear,
300
What is nuclear fusion? - answer to include size of reactants joining /splitting mass energy
When two very small nuclei join together to produce a slightly larger nucleus with a mass, less than the sum of the reactants. This loss of mass is released as THERMAL energy.
400
Who is attributed with discovering the electron?
Joseph Thomson
400
List in detail, the 4 key elements of Rutherford's experiment
Vacuum, 100 atom thick gold foil, alpha particles (He nucleus), movable or semicircular fluorescing (Zinc Sulfide) screen.
400
How do you find the number of neutrons if you are only given the atomic number and the atomic mass
Neutrons = Mass - atomic number
400
ANSWER B ONLY Nuclei with low numbers of nucleons are stable because they are held together by the _______A_________ force. Eventually the __________B___________ force takes over and the nuclei become less stable.
Electromagnetic repulsion
400
If there is a magnetic field coming up out of your desk and a beta radiation source is coming out of you over the desk, which way will it bend?
to the left (Beta is negative - left hand rule - fingers up, thumb away)
500
Who placed the atoms in orbits around the nucleus? AND who is attributed to the discovery of the Neutron?
Niels Bohr / James Chadwick
500
Detail the four conclusions that Rutherford made from his observations
1.Atom mostly space. 2. Mass all together in centre. 3. Centre is positive. 4. Electrons must be around the outside.
500
An atomic symbol with the mass and atomic number written near it is called what? AND how many neutrons does Iodine 131, 53 have? DOUBLE POINTS!! what is radioactive Iodine used for?
A Nuclide, 78, Double points - treating a cancerous thyroid (or lung or kidney)
500
Calculate the half life of an isotope if its activity falls from 1600 counts per second to 400 counters per second after 60 days.
30 Days
500
Radon with a mass of 1 decays to Polonium with a mass of 0.98194467 the decay releases a heap of Alpha particles that weigh 0.00002703 in total. How much energy was released?
1.62254 x 10^15 (times ten to the fifteen) Joules
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