Nuclear Chemistry

review labs, worksheets, notes

nuclear fission

bombard the nucleus with neutrons, splits nucleus into smaller fragments; releases energy

nuclear fission chain reaction

neutrons are also products of this reaction and can be used to start another reaction

nuclear fusion

light mass nuclei combine to form a heavier nucleus

example of nuclear fusion

hydrogen bomb, sun

why is nuclear fusion better than fission?

generates more energy and doesn’t produce radioactive substance

what type of reactions do nuclear power plants use?

nuclear fission

nuclear half life

time required for half the atoms of a particular radioisotope to decay into another isotope

half life formula

The half life of cobalt-60 is 10.47 minutes. How much cobalt is remaining after 180 minutes starting with 2000 grams?

0.01 grams left

radioactive decay

spontaneous disintegration of nucleus into slightly lighter nucleus accompanied by emission of particles, electromagnetic radiation, or both

alpha decay

releases α particle, or a helium nucleus (⁴₂He)

what blocks alpha rays?

paper

beta decay

loss of β- particle (high energy electron); neutron turns into proton, emits electron (⁰_-1e)

what blocks beta rays?

metal foil

gamma decay

loss of γ high-energy radiation (₀⁰γ), usually occurs immediately following other types of decay

what blocks gamma rays?

lead/concrete

what is the most dangerous radiation?

gamma rays

positron/beta plus decay

proton converted to a neutron, and a positron + neutrino is sent out (don’t need to show neutrino)

neutrino

“ghost particle” has no mass or charge

positron

anti matter equivalent of an electron

neutron emission

one or more neutrons are ejected from a nucleus; atom becomes a different isotope

band of stability

diagram that plots N (neutrons) vs Z (protons) to show stability of known elements

for which elements is the N:Z ratio about 1:1?

elements with less than 20 protons

when do elements undergo beta decay?

when the dot is above the band of stability (more neutrons, less protons)

when do elements undergo positron decay?

when the dot is below the band of stability (less neutrons, more protons)

when do elements undergo alpha decay?

for elements with 82+ protons

how does a pressurized water reactor work?

it uses nuclear fission to heat up water that turns into steam and drives a turbine to generate electricity

what do control rods do?

control chain reactions by absorbing neutrons