Nuclear Chemistry 1.1

Alpha Emission- nucleus emits an alpha particle which consists of 2 protons and 2 neutrons, positively charged with a mass number of 4

After alpha emission, the atom will have two fewer protons and two fewer neutrons CHANGE ELEMENTS
Relatively large, slow-moving particle, blocked by a sheet of paper

Beta Emission- The nucleus emits a beta particle which is a high-speed electron, negatively charged with a mass number of 0

Beta particles form when a neutron is converted into a proton and an electron, (the electron gets ejected from the nucleus)
After beta emission, the atom will have one less neutron but one more proton
Massless, fast-moving particle, blocked by 100 sheets of paper

Gamma Emission- The nucleus emits a photon of pure energy, no charge, and no mass

High energy, very penetrating, not completely blocked by lead, present with almost every other radioactive emission

no change to the atom

Positron Emission- The nucleus emits a beta plus particle which is called a “positron”

positively charged with a mass number of 0
Formed in the nucleus when a proton is converted into a neutron and a positron is ejected
massless, positively charged particle
doesn’t penetrate matter because it quickly collides with electrons after leaving the nucleus and produces gamma radiation

Electron Capture- The nucleus absorbs an electron

An inner shell electron is pulled into the nucleus where it combines with a proton to form a neutron.
During electron capture, the atom loses an electron and a proton but gains a neutron

Results in the emission of an X-ray as a higher energy electron moves to a lower energy level to fill the vacancy left by the captured electron

All atoms with more than 83 protons are radioactive
No number of neutrons can exert enough force to overcome that much repulsion
Any atom that does not have the optimum proton-to-neutron ratio is defined by the “belt of stability” graph.

Half-Life

Half life- The amount of time it takes for half of a sample to react or decay.

The half-life of specific radioisotopes is constant but varies for each type of @@element@@
Radioactive decay processes follow a “1st order” rate law which means that the time it takes for half of a sample to decay is @@independent@@ of the size of the sample.

The half life of a radioactive decay process does not change based on how large or how small the sample is.

amount remaining=initial amount * (1/2)^n

Bombardment- Small high-speed particles are fired at the nuclei of atoms causing a change inside the nucleus, going INTO the nucleus

- This change can result in huge releases of energy

- If two or more atoms slam into each other with enough energy and speed, their nuclei might fuse or join together to become one new, larger nucleus.

- Requires high temps, used in hydrogen bombs

The splitting of a heavy nucleus into smaller fragments by hitting it with a high-speed particle (often a neutron)

Used at nuclear power plants to produce electricity and used to make nuclear bombs.