Theme one - Radioactive decay Flashcards
Define element
A pure chemical substance characterized by the number of protons present
what is Z in an atom?
The atomic number (amount of protons)
What is A in atoms?
The total number of protons + neutrons (mass number)
What is relative atomic mass?
the ratio of the average mass of atoms in an element in relation to 1 hydrogen atom. (the weight of 1 mol of a substance is its relative atomic mass)
What is radioactive decay?
the process by which unstable nucleotides/atoms transform into other stable/unstable isotopes via the admittance of alpha,beta particles, or gamma radiation
What is atomic mass unit?
a mass equal to 1/12th of the mass of a C12 atom
how do parent radionuclide decay?
Via a radioactive decay series
How does a daughter element differ from a parent element when radioactive decay occurs via alpha particle emisssiom?
An atomic number (z) two less than parent, and mass number (a) 4 less
what is an alpha particle?
A hydrogen atom ( two protons and two neutrons)
what is a beta particles? how do they form?
a high speed electron that is emitted when a neutron in the nucleus is converted to a proton
how do daughter isotopes differ from parent isotopes in beta decay?
unchanged mass number, atomic number 1 greater than parent
what are the three isotopes oh hydrogen and which are unstable?
1H, 2H (deuterium, stable)
3H(titrium, unstable)
All have one proton
How does 3H form in the atmosphere?
naturally in the upper atmosphere via cosmic ray bombardment, or artificially via nuclear weapons/power
what are the two (out of 9) stable isotopes of carbon?
12C and 13 C
How many of carbon atoms are unstable and how many protons do they have?
7 unstable with 6 protons. 14C is commonly used for dating methods
how many isotopes of uranium are there? how many protons and how many are unstable?
9 isotopes each with 92 protons. ALL are unstable. 3 are natural (238U,235U,234U)
Which form of uranium has a 17 step decay series?
238U
what are nuclear forces and how do they impact atom stability?
forces that act between two or more nucleons, binding protons and neutrons into an atomic nuclei. Stable atoms have BALANCED NUCLEAR FORCES
how does mass impact atom stability?
atoms with lower masses are generally more stable. .
what ratio dictates isotope stability?
The neutron/proton ratio. this is variable between species.
What are the ideal neutron to proton ratios for large and small isotopes?
Small= 1:1 Large= 1:1.5
what is the stability zone and how does this influence half life?
The stability zone is the zone in which isotopes have the correct neutron:proton ratio to remain stable, and the further away from this the lesser the atom half lives.
