module 1 Flashcards
what are atoms?
-composed of a nucleus with radius 10^-14m and a surrounding cloud of electrons travelling in orbits of 10^-10m
-the nucleus is composed of nucleons: protons and neutrons
what is atomic structure?
what are isotopes?
-same number of protons but different number of neutrons
(both hydrogen)
what are isotones?
-same number of neutrons but different number of protons
(different elements)
what are isobars?
-same number of nucleons but different number of protons
(different elements)
what are isomers?
-the same number of protons and neutrons (differ in nuclear energy state)
(same element, with an m)
-m=metastable, meaning the nucleus is in an excited state
what is a proton?
1 1 H
-charge is +1
-the nucleus of a hydrogen atom
-mass is 1.007277 amu
what is a neutron?
-charge is zero
-mass is 1.008665 amu
what is an electron?
-also known as a beta particle or ray, or a beta minus particle or ray
-charge is -1
-mass is 0.000548 amu
what is a positron?
-also known as a beta plus particle or ray
-identical to an electron but with a positive charge
-charge is +1
-mass is 0.000548 amu
-exist only when in motion (when they slow or stop moving they combine with an electron and annihilate)
what is a photon?
-not technically a particle, but behaves as a particles at higher energies
-charge is 0
-mass is 0
-a bundle of energy travelling at the speed of light
-photons include x-rays and gamma rays
what is the only difference between x-rays and gamma rays?
their mode of origin (both photons)
-X-rays: arise from transitions of electrons between shells of an atom or from interaction between electrons and nuclei
-gamma rays: ejected from a nucleus
what are alpha particles?
-charge is +2
-the nucleus of a helium atom (2 protons and 2 neutrons)
-mass is 4.001506 amu
what is the summary of subatomic particles?
what is the definition of radiation?
-any combination of subatomic particles with sufficient kinetic energy to interact with, and transfer energy to, objects that intersect their path
-radiation can be ejects by radioactive nuclides or be generated by machines
what is the difference between excitation and ionization?
-excitation involves the displacing of an orbital electron from its ground state
-ionization involves the removal of an orbital electron from a neutral atom