Atomic Structure Flashcards
What is relative atomic mass?
The “weighted mean” mass of an atom relative to 1/12th of the mass of a carbon-12 atom
What is isotopic mass?
The mass of an atom of an isotope relative to 1/12th of the mass of a carbon-12 atom
How do you calculate the relative atomic mass of two isotopes?
Multiply the atomic mass by the percentage
Divide by the two percentages added together (they must add to give 100)
Why are neutrons present in the nucleus?
Provide binding so that the protons don’t repel each other
What is the charge and mass of a proton?
+1
1
What is the charge and mass of a neutron?
0
1
What is the charge and mass of a electron?
-1
1/1836
What are isotopes?
Atoms of the same element but with a different number of neutrons but same number of protons
What are the 3 isotopes of hydrogen?
Protium
deuterium
Tritium
What is the formula for ammonium?
NH4 +
What is the formula for nitrate?
NO3 -
What is the formula for sulfate?
SO4 2-
What is the formula for hydroxide?
OH -
What is the formula for phosphate?
PO4 3-
What is the formula for carbonate?
CO3 2-
What is the formula for permanganate?
MnO4 -
What is the formula for dichromate?
Cr2O7 2-
What is the formula for chromate?
CrO4 2-
What is the formula for peroxide?
O2 -
When writing ionic equations what do you do?
Write out the ionic equation
Eliminate spectator ions
Don’t include giant structures eg. solids or covalent bonds
Why did Niels Bohr think Rutherford’s model was wrong?
Electrons couldn’t be freely orbiting as if this was true they would spiral into the nucleus
So he said they were in a fixed orbital/shell
According to Bohr, what happens when electrons in an atom move from one shell to another?
Electromagnetic radiation is emitted or absorbed
How do you know if something is polar?
If it has all the same elements attached + lone pair
Or
If it hasn’t got al the same elements + no lone pair
How do you know if something is non-polar?
If something hasn’t got all the same elements + lone pair
Or
If it has all the same elements + no lone pair