Chem 1 Atomic Structure and Nuclear Chemistry
Atomic Mass
The weighted average mass of an element's isotopes.
Determined the mass-to-charge ratio of an electron
Thomson
The type of radioactive particle that can be stopped by a sheet of paper is the ____.
Alpha Particle.
A helium nucleus with two protons and two neutrons is called a(n) ____.
Alpha particle.
Isotopes
Atoms with the same number of protons but different numbers of neutrons
Fast-moving electrons.
Beta Radiation
A(n) _____ is a high energy electron.
Beta particle.
A particle that moves around the nucleus is a(n) ____.
Electron.
The most penetrating type of radiation is the ____.
Gamma Ray
Gamma Ray
High-energy radiation that has no charge and no mass
Fusion reactions require ____.
Incredibly high temperatures.
Atoms of the same element with different numbers of neutrons are called ____.
Isotopes.
Calculated the mass of an electron
Millikan
The number of stable isotopes that exist compared to the number of unstable isotopes is _____.
Much less.
A reaction that involves a change in an atom's nucleus.
Nuclear reaction
Energy
One product of all nuclear fission reactions.
Radioactive Decay
Process (not requiring energy) by which unstable nuclei lose energy
Radioactivity
Process whereby some substances spontaneously emit radiation
Both a fusion reaction and a fission reaction ____.
Produce energy.
The rays and particles that are emitted by a radioactive material.
Radiation
Alpha Radiation
Radiation deflected toward the negatively charged plate
Beta Radiation
Radiation deflected toward the positively charged plate.
The process in which an unstable nucleus loses energy spontaneously
Radioactive Decay
Proposed the nuclear atomic model
Rutherford
The mass of an electron is _____.
Smaller than the mass of a proton, a tiny fraction of the mass of an atom, smaller than the mass of a neutron.
Dalton's Atomic Theory
States that all matter is composed of atoms
Nucleus
The center-most part of an atom where the protons and neutrons are contained
Gamma Rays
The most penetrating form of nuclear radiation.
Radiation
The rays and particles emitted by radioactive material
Atom
The smallest particle of an element that retains the properties of that element.
Thorium-234 has a half-life of 24 days. If you started with a 100-g sample of thorium-234, how much would remain after 48 days?
25g
The half-life of calcium-47 is about 5 days. Starting with 64 g of this isotope, what would be the amount remaining after 20 days?
4g
A certain atom has 26 protons, 26 electrons, and 30 neutrons. Its mass number is ____.
56
Which of the following isotopes is not commonly used for dating objects?
phosphorus-32
