Atoms Flashcards
Atoms are made up of…
Protons
Electrons
Neutrons
The charge of a proton is.... The mass of a proton is... The charge of an electron is... The mass of an electron is... The charge of a neutron is... The mass of a neutron is....
\+1(Positive) 1 -1 (Negative) Almost 0 0 (Neutral) 1
The radius of an atom is…
_____________________-10 __
about 0.1nm or 1 x 10 m
The radius of a nucleus from an atom is….
______-14__
1 x 10 m
The radius of a nucleus is ________ times smaller than the radius of an atom
10,000
14
C The lower number is the….
6
Atomic Number (the number of protons)
14
C The higher number is the….
6
Atomic Mass (protons + neutrons)
14
C The higher number is the….
6
Atomic Mass (protons + neutrons)
To calculate the number of neutrons in an atom….
Take away the Atomic Number from the Mass Number.
Mass Number - Atomic Number
Who discovered atoms and at what date?
Democritus in 400 B.C.
What idea about atoms did J.J. Thompson come up with?
The atom was itself positive and the electrons which were negative were placed in side of it.
This was called the Plum Pudding Model.
Rutherford carried out an experiment where he shot alpha particles at a very thin layer of gold (gold leaf), but the results didnt come back as expected, what happened?
Due to the belief that the atom was fully positive (Plum Pudding Model) due to the idea put forward by J.J. Thompson Rutherford thought that the majority of the atoms would be reflected back however some completely passed through, some deflected and some of them reflected. This therefore made the discovery of 3 things:
1) Most of the atom was empty space (passed straight through)
2) There was a Nucleus in an atom (some of the atom was deflected because of the nucleus in the gold.
3) There were protons in an atom which were completely reflected.
What did Bohr do?
He put the electrons into shells.
What did James Chadwick discovered?
Neutrons
What order did the Protons, Neutrons and Electrons get discovered in?
1st Electrons
2nd Protons
3rd Neutrons
