electron volt (eV) Very small amount
Contains most of the mass of atoms (neutrons and pro-
Nucleus
tons)
Electron cloud Electrons surround cloud
Electron 0 charge
Neutron -1 charge
Proton +1 charge
Nucleons protons and neutrons in the nucleus
Generic term for a combination of nucleons (protons and
Nuclide
neutrons)
Atomic (proton #) Z
mass number A
Neutron number N
Isotopes Same Z (proton #)
Isobars Same A (mass #)
Isotones Same N (neutron #)
Isomers Same Z, A, N, and differ only in energy level
a nuclide with a nucleus that does not readily undergo
stable nuclide
change
Combination of protons and neutrons within the nucleus
stable nuclide
result in a nucleus that is stable
n/p ratio neutron to proton ratio
In stable nuclides, the n/p ratio had to be close to 1; Z
for low and close to for high 1.5; Z
unstable nuclide
, a nuclide with a nucleus that spontaneously undergoes
change (wishes to be stable)
T/F: In unstable nuclides, the n/p ratio is never = to 1 T
In unstable nuclides, the n/p ratio is or than Greater; less; 1; Z
for low Z and or than for high Greater; less; 1.5; Z
A device used to accelerate charged particles to high en-
Cyclotron
ergies for bombarding the nuclei of atoms.
reactor the part of a nuclear reactor where nuclear fission occurs
Fission The splitting of an atomic nucleus to release energy.
Alpha particles are Helium nuclei (2 protons 2 neutrons) (positive charge)
Single charge either + or -
Beta particles (negatron) (positron)
Mass of an electron
No charge, no mass
Gamma ray (photon)
Packet of energy
alpha decay Usually occurs in RN that are unstable due to large mass
Beta Decay (negatron emission) Occurs when nucleus is unstable due to n/p ratio too great
T/F: A neutron is converted to a proton by getting rid of
T
the negative component called negatron
Certain RN will emit a negatron due to neutron excess but
Beta-gamma decay there is still excess energy remaining within the nucleus
and is emitted as a gamma ray
RN emits a negatron and the resulting daughter still con-
tains excess energy but there is a measurable amount of
Gamma decay (isomeric transition)
time between the emissions-allowing measurements of
the T1/2 of the daughter
Internal conversion
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