Early Ideas About Matter
Philosopher that was the first person to propose the idea that matter was not indefinitely divisible.
Who is Democritus?
This part of the atom is responsible for 99.97% of its mass.
What is the nucleus?
the number of protons displayed on each box for an atom on the periodic table
what is the atomic number?
Unstable nuclei lose energy by emitting radiation in a spontaneous process
What is Radioactive Decay?
Philosopher concerned the idea that atoms moved through empty space.
Who is Aristotle?
Protons and electrons carry _____ but opposite charges.
What is equal?
what is mass number?
Which particle is positively char burning radioactive decay?
What is an alpha particle?
Scientist that was able to determine the mass ratios of the elements involved in chemical reactions.
Who is John Dalton?
In a cathode ray tube, electrons travel from the cathode to the _____.
What is an anode?
the vertical boxes numbered 1-18 on the periodic table
what is group/family?
What composition and electric charge has 1 electron and a single negative charge?
What is a beta particle?
States that mass is conserved in any process.
What is The Law of Conservation of Mass?
The Gold Foil Experiment disproved this early model of the atom.
What is the Plum Pudding Model?
the average mass of all of the isotopes in an atom
what is the atomic mass?
High energy radiation that has no mass and denoted by the symbol γ
What is a gamma ray?
They tested the validity of their ideas with the scientific method.
What is Philosophers thousands of years ago?
The tool that is used to 'see' atoms
What is the Scanning Tunneling Microscope?
atoms with the same number of protons and electrons but multiple different numbers of neutrons
An atoms stability is governed by its ratio of neutrons to proton. Atoms that contain too much or too little neutrons are unstable and loose energy
What is the nuclear stability of an atom?