Chemistry Half-Life and Balancing Nuclear Equations

nucleons

particles occupying the nucleus

which particles are considered nucleons?

protons and neutrons

in nuclear notation, the top number is the?

mass number

in nuclear notation, the bottom number is the?

atomic number

isotopes

atoms of the same element with different number of neutrons (different masses)

strong forces

forces of attraction between nucleons

are strong forces short range or long range?

short range

electrical force

force of repulsions between positively charged protons

are electrical forces short range or long range?

long range

when are nuclei unstable?

when electrical forces of repulsion are greater than strong forces of attraction

radioactive isotope

unstable nucleus, spontaneously emits a particle and decays into another element

transmulation

changing into another element through radioactive decay

what are the three types of radioactive transmission?

alpha, beta, and gamma

alpha

made of 2 protons and 2 neutrons, heaviest particle, slowest moving, stopped by paper

beta

made of 1 electron (negative charge), slightly faster moving, stopped by aluminum

gamma

made of energy (no charge), fastest moving particle, stopped by lead

what happens during beta decay?

a neutron changes into a proton and an electron

half-life

the time it takes for half the mass of a radioactive sample to decay

half-life is not affected by?

external conditions

what determines an element's identity?

the atomic number (number of protons)