Atomic Structure Flashcards
What does mass spectrometry determine?
Relative atomic masses.
Why is mass spectrometry done under a vacuum?
To prevent the ions produced from colliding with molecules from the air.
Who discovered the neutron?
James Chadwick.
In mass spectrometry what stage is after Ionisation?
Acceleration.
What is the relative mass of an electron?
1/1840
Where does the electron ‘live’ in the atom?
The atomic orbital.
What do the shapes in atomic orbitals represent?
A volume of space in which there is a 95% probability of finding an electron.
How many electrons can an atomic orbital hold maximum?
2
What is spin?
A property of electrons
That two electrons in the same orbital must have opposite spins.
Why is 4s filled before 3d?
4s has a lower energy.
What is ionisation energy?
Energy required to remove a mole of electrons from a mole of atoms in the gaseous state and is measure in kJmol-1.
Why does the first electron usually require the least energy to be removed from an atom (subsequent ionisation energies)?
It’s is being removed from a neutral atom.
Using low resolution mass spec, how can you work out the Ar/Mr of an element?
Add together the relative abundances of the isotopes detected multiplied by the mass/charge ratio of the same isotope, then divide by 100.
What are successive ionisation energies?
The charge of an ion increasing based on the energy required to remove each electron.
Why are the two electrons on the S2 sub level so hard to remove from the atom?
They are the closest to the nucleus and thus the nearest to the positive charge of the nucleus.
