Atomic Theory Flashcards
What’s an isotope ?
Atoms of an element that have the same number of protons and a different number of neutrons
Democriticus was who ?
A 5th century greek philosopher who found out that elements contain the tiny particles of atoms
Who created the solid sphere model ?
John Dalton in 1893
What model did J.J Thompson create ?
The plum pudding model
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Who created what model in 1911?
Earnest Ruthford - nuclear model
Niels Bohr created what model in 1913?
The planetary model
(Shells surrounding positive nucleus )
Erwin Schrödinger designed what atomic model when?
Quantum Model in 1926
What did Chadwick do In 1932?
Applying the laws of conservation of mass & energy he deduced that the mystery particles remaind unchanged
How many atoms belong in first shell?
2
How many atoms belong in the 2nd shell?
8
How many atoms belong in the 3rd shell?
8
How many atoms belong in the fourth shell?
18
How do you work out relative atomic mass?
(Mass x%) + (mass2 x %)
————————————
100
Properties of a proton?
Found in nucleus
Relative mass of 1
Relative charge +1
Properties of a neutron
Found in nucleus
Relative mass of 1
Relative charge 0
Properties of an electron
Found in shells
Relative mass negligible
Relative charge -1
Calculation for the relative formula mass?
1 work out number of each element
2 find relative atomic mass on periodic table
3 multiply steps one 1&2
4 add together relative atomic masses
5 step 3 decided by step 4 x 100
What are the names of the three types of Hydrogen
H. 2H. 3H
hydrogen peutruim. Tritiam
Why do most of the alpha particles pass through gold atoms ?
As most of the space inside is empty
Why do some alpha particles deflect or bounce back
Due to repellent force between nucleus positive charge and
Define the term atomic number
The number of protons
Define the term mass number
Protons + neutrons
The number of protons are also =_____________
Electrons
