P1P2C3 - Atomic Structure Flashcards
How many elements have been discovered?
118
What is a compound?
Two or more elements chemically bonded together
Who is John Dalton?
In 1803, he suggested that all matter is made of atoms and cannot be split.
Who is JJ Thompson?
In 1897, he discovered electrons and modelled the as a ‘Plum pudding’.
Who is Earnest Rutherford?
In 1909, he discovered that alpha particles could bounce off atoms.
And that there was a nucleus in the centre of an atom with protons.
His model was called the nuclear model.
Who is Niels Bohr?
He discovered electrons orbit the nucleus.
Who is James Chadwick?
In 1932, he discovered neutrons.
What is the radius of an atom?
0.1 nanometres
1x10^-10
What is an isotope?
Same n.o of protons
Different n.o of neutrons
What are the 3 isotopes of hydrogen?
Protium
Deuterium
Tritium
What is a nuclide?
- A type of isotope
- Refers to a specific nucleus that contains a certain number of protons and neutrons.
How do you calculate relative atomic mass in an isotope?
Relative mass =
(Mass n.o of isotope) X (abundance of isotope 1)
+
(Mass n.o of isotope 2) X (abundance of isotope 2)
————————————————-
100
75% of Cl atoms have a mass number of 31, whilst the remaining 25% have a mass number of 40. What is the relative atomic mass of chlorine?
(75 X 31) + (25 X 40)
—————————- = 33.25
100
What is the shorthand for relative atomic mass?
Ar
