1. Particles Flashcards
Name the two nucleons that make up an atoms nucleus.
Protons and Neutrons
What is the name of the particle that orbits around the atom in energy shells?
Electrons
Order the 3 particles of an atom in order of highest mass to lowest.
Neutron (1.67(5) x 10^-27), Proton (1.67(3) x 10^-27), Electron (9.11x10^-31)
Which atomic particle has a relative charge of +1.
Proton
Which of the atomic particles is neutrally charged?
Neutron
What is the proton number?
Sometime known as the atomic number, and it is the number of protons in the atoms nucleus. This number determines what element it is.
In a neutral atom, if the atom had 6 protons, how many electrons are there?
6 electrons
What is the nucleon number?
It is the total number of neutrons and protons in the nucleus. Also known as the mass number.
If carbon has a nucleon number of 12 and a proton number of 6, how many neutrons does it have?
12 - 6 = 6 neutrons
Define isotopes.
Atoms with the same number of protons but different numbers of neutrons. This means the atom remains the same element but the mass of the nucleus changes.
What does the number of neutrons in an atom affect in the nucleus?
It’s stability. Unstable nuclei may be radioactive and decay over time to become more stable.
Name a use of radioactive isotopes.
Used to find out how old objects are. All living things contain the same percentage of radioactive carbon-14 taken from the atmosphere. This percentage decreases when the thing dies, due to decay. The age can be approximated for dead organic matter.
Define specific charge.
It is the ratio of a particles charge to its mass.
What is the unit of specific charge?
C/kg
What is the specific charge of a proton?
SC = charge/mass => (1.60 x 10^-19)/(1.67 x 10^-27)
= (9.58 x 10^7)
Name the four fundamental forces.
Strong nuclear, weak nuclear, electromagnetic and gravitational.
What is the strong nuclear force?
An attractive force that opposes the the electromagnetic force, holding nucleons in the nucleus.
What force is stronger, strong nuclear or electromagnetic?
Strong Nuclear.
Does the strong nuclear force have a very large range of a very short range?
Very short range, it can only hold nucleons together that are separated by up to a few femtometres.
What does 1 femtometre equal in metres?
1fm = 1 x 10^-15 m
The strength of the _________ attractive force quickly falls beyond a couple of femtometres.
Strong nuclear
When is the strong nuclear force repulsive?
At very small separation between the nucleons, so that the nucleus doesn’t crush to a point.
Does alpha emission only occur in very large nuclei or very small nuclei?
Very large. This is because the nucleus is so large for the strong force to keep the nucleons together.
Give an example of a element that can emit alpha radiation.
Uranium and radium.