Created the Law of Conservation of Matter
Created the Atomic Theory of Matter
Came up with the idea of Atoms.
Created Law of Constant Composition
Opposite charges, positive and negative.
Plum Pudding model. Positively charged goo with negative chunks randomly scattered.
Devised the "Gold Foil Experiment" to confirm PP Model
Positively charged, composed of protons
Have no charge, exert a "strong nuclear force"
Orbit the nucleus, negatively charged
What do protons identify?
Changing protons results in
When you change the number of electrons an atom becomes an
No charge, the smallest particle of an element that behaves like that element. Cannot be chemically or physically divided.
Positive charge, results from losing electrons
Negative charge, results from gaining an electron
Atoms that have the same number of protons but different number of neutrons
Chemically, stable Isotopes behave
Why do we ignore electrons when accounting for atomic mass?
Because they weigh so little
Number of protons: 1/Number of Neutrons required for Stability:
Number of protons: 2-19/Number of Neutrons required for stability:
Equal number of neutrons and protons
Number of protons: 20-83/Number of Neutrons required for stability:
More neutrons than protons
Number of protons: 84+/Number of Neutrons required for stability:
The emission of something
Emission of nuclear particles (protons, neutrons...)
one nucleus breaking down into multiple nuclei
an alpha particle is a helium nucleus (2 protons + 2 neutrons) least dangerous
a single neutron breaks into 1 proton and electron. Proton is absorbed by the parent nucleus, the electron is emitted at high speed.
Pure high energy
The amount of time required for half of a sample to undergo decay
two atoms are bombarded to form a larger nucleus. (often unstable).
a nucleus will break apart into two larger other chunks (two separate nucleii)