Chapter 7 Flashcards
what is radioactivity?
a release of high-energy particles and rays of energy from a substance
what is radiation?
high-energy rays and particles given off by things that are radioactive
what are isotopes?
another way of representing an element
they have the same # of protons and a different # of neutrons
how to you find the number of neutrons in an isotope?
number of neutrons = mass number - atomic number
how do you find the mass number of an isotope?
mass number = atomic # + neutrons
how do you represent isotopes?
using standard atomic notation or nuclear symbol
ex. Potassium-39
what is radioactive decay?
the process of an unstable nuclei emitting radiation to stabilize itself
what are 3 types of radiation?
alpha
beta
gamma
what are 4 facts about alpha radiation?
1) a stream of alpha particles
2) charge of 2+
3) can be stopped by paper
4) looks like a helium element
what are 4 facts about beta radiation?
1) a stream of beta particles
2) charge of -1
3) can be stopped by aluminum
4) also an electron element
what are 3 facts about gamma radiation?
1) rays of high-energy with short wave lengths
2) charge of 0
3) can by stopped by lead
what is radiocarbon dating?
the process of finding the age of an object by measuring the amount of Carbon-14 remaining
what is a half life?
a measure of the rate of decay for an isotope, it is equal to the time is takes for half of the nuclei to decay
what is a decay curve?
a curved line on a graph that shows the rate of a radioisotope decaying
how do you set up a graph for decay?
title: decay of _______
y-axis: _____ remaining (%)
x-axis: _____ # of half lives
what are common isotope pairs?
parent and daughter isotopes
what is a parent isotope?
an isotope that undergoes radioactive decay
what is a daughter isotope?
the stable product if radioactive decay
what is the potassium-40 clock?
what radioisotopes are used, usually potassium-40 and argon-40, to date objects
what does the atomic theory state?
protons and neutrons are in the nucleus
electrons surround the nucleus
what are 2 types of nuclear reactions?
fission and fusion
what is nuclear fission?
when a nuclei splits, produces 2 nuclei, and releases energy and a subatomic particle
what is an induced nuclear reaction?
when scientists bombard a nucleus with alpha, beta, gamma rays
how long can a fuel bundle be in a candu reactor for?
15 months
