Topic 1 - Atomic Structure Flashcards
What is the mass number?
The total number of protons and neutrons in the nucleus
What is the atomic number?
Number of protons in the nucleus
What is an isotope?
Atoms with the same number of protons but different number of neutrons
Why do isotopes have the same chemical properties?
chemical properties are decided by number and arrangement of electrons and isotopes have the same configuration of electrons
Why do isotopes have different physical properties?
Because physical properties depend on mass of the atom and isotopes don’t always have the same mass
What is the relative atomic mass?
The weights mean mass of an atom of an element, compared to 1/12th of the mass of an atom of carbon-12
What is relative isotopic mass?
Mass of an atom of an isotope compared with 1/12th of the mass of an atom of carbon-12
What is the relative molecular mass?
The average mass of a molecule or formula unit, compared to 1/12th of the mass of an atom of carbon-12
How do you find relative atomic mass from its isotopic abundances?
Multiply each relative isotopic mass by its % relative isotopic abundance, add up the results and divide by 100
How do you work out relative isotopic abundance from mass spectra?
You find the height of the peak
What is on the x axis of the mass spectra graph?
It is the M/Z value which is mass/charge.
What is on the y axis of the mass spectra graph?
The abundance of ions, often as a percentage
How do you work out the relative isotopic mass when the charge is 1+?
It is the number on the x-axis with a peak (m/z value)
How do you work out the relative atomic mass from a graph?
Multiply each relative isotopic mass by its relative abundance, add up the results than divide by the sum of the isotopic abundances
What is the first step of calculating isotopic masses from relative atomic mass?
Finding the abundance the missing isotope, by minusing the previous percentages by 100%
What is the second step of calculating isotopic masses from relative atomic mass?
Plot the information into the equation relative atomic mass = 1st isotope
(abundance * isotopic mass) + 2nd isotope (abundance * isotopic mass) divided by 100. Then calculate for X
How do you find relative molecular mass of a compound?
Through the use mass spectrometry, you find the highest m/z value, the value is the molecular mass
How are molecular ions formed?
when molecules in a sample are bombarded by electrons, causing an electron to be removed from the molecule
What is the name for the highest m/z value peak?
molecular ion peak (assuming the ion has a +1 charge)
What are principle quantum numbers?
Represents the relative overall energy of each orbital
What happens to shells further from the nucleus?
They have a greater energy levels the further from the nucleus they are
What is an orbital?
The bit of space than an electron moves in
What is spin-pairing?
When electrons in each orbital have to spin in opposite directions
What are the two types of orbitals?
s-orbital spherical shaped and p-orbital dumbbell shape
How are orbitals filled?
They are filled up from the lowest energy subshells first and fill singly first before pairing up
How and Why do chromium and copper behave differently?
They donate an electron from the 4s subshell to the 3d subshell, as they are more stable with a full or half-full d-subshell
What is electromagnetic radiation?
Energy that is transmitted as waves, with a spectrum of different frequencies
What happens along the electromagnetic spectrum?
Radiation increases in frequency and decreases in wavelength
