P4- Atomic Structure Flashcards
What is the order for the discovery of sub atomic particles?
EPN
How did John dalton describe atoms?
Solid spheres
The smallest possible unit
Different sizes for different elements
What is the radius of an atom?
1*10-10
What did JJ Thompson do?
Plum pudding model and discovered electrons
What did Rutherford do?
Scattered alpha particles at a leaf of gold foil 1909
What happened to the alpha particles in Rutherford experiment?
Some were:
Went through
Deflected
Reflected
What was Rutherford conclusion?
There was more mass in the nucleus and a cloud of negative charge around
What did Bohr suggest?
Electrons orbit the nucleus at fixed distances in shells
What is the model we use today?
The nuclear model
What was the order of the development of the atom?
Democritus
Dalton
Thompson
Rutherford
Bohr
Rutherford (protons)
Chadwick
How do you do an alpha equation?
Decrease mass number by 4
Decrease atomic number by 2
How do you do a beta equation?
+1 in atomic number
How do you do an equation for gamma?
No change
How do you do a neutron emission equation?
-1 from mass number
Nuclear fission
Splitting up of unstable nucleus by firing a slow moving electron making it even more unstable and producing energy
Chain reaction
Where can we find uncontrolled fission?
Nuclear bombs
How do we control rate of fission in nuclear reactors?
Control rods lowered into reactor to absorb neutrons and slow down the rate of fission
How does fission produce electricity?
Energy produced (gamma radiation) heats up water which turns to steam that turn turbines and is connected to an electricity generator
What is the product of fission?
Lots of energy (gamma radiation)
More neutrons
2 daughter nuclei
Pros of fission
Uranium or plutonium fuel is relatively cheap
Large and consistent amounts of energy
Doesn’t produce greenhouse gases
Cons of fission
Power plants are expensive to build
Nuclear waste is radioactive and is expensive to store in underground bunkers
Risk of disaster if nuclear meltdown
What is nuclear fusion
?
Combining 2 light nuclei to make a heavier nuclei and release lots of energy
The heavier nuclei will always be lighter than the total of the 2 light nuclei because some mass is converted to energy
What temperature does fusion happen?
10,000,000*c
Where does fusion happen?
Only in stars
