Topic 1 - Atomic Structure and Periodic Table Flashcards
what is the relative charge of a neutron?
0
what is the relative charge of an electron?
-1
what is the relative charge of an proton?
+1
what is the relative mass of a neutron?
1
what is the relative mass of a proton?
1
what is the relative mass of an electron?
1/1840
what is an isotope?
atoms with the same atomic number, but different mass number
what is relative isotopic mass?
the mass of one atom of an isotope compared to 1/12th of a carbon-12 atom’s mass
what is relative atomic mass?
the average mass of one atom compared to 1/12th of a carbon-12 atom’s mass
what is relative molecular mass?
the average mass of one molecule compared to 1/12 of a carbon-12 atom’s mass
what do the different peaks on a mass spectrometry graph mean?
they represent the different fragments of ions
what is first ionisation energy?
the energy required to remove one mole of electrons from one mole of gaseous atoms
what are the three factors affecting first ionisation energy?
- atomic radius
- nuclear charge
- electron shielding
how does atomic radius affect ionisation energy?
the bigger the atom, the further away the outermost electrons will be from the nucleus and the weaker the attraction
how does nuclear charge affect ionisation energy?
the more protons that are in the nucleus, the stronger the electrostatic attraction between the electrons and the nucleus
how does electron shielding affect ionisation energy?
the inner electron shells that are filled repel the outer (valence) electrons
why is the second ionisation energy always bigger than the first?
when one electron is removed it leaves a positive ion, increasing the attraction between the nucleus and electrons
what does a big jump between ionisation energies indicate?
the smaller ionisation energy shows the group of the atom, because a new electron in a new shell takes more energy to remove
what is periodicity?
a regularly repeating pattern of atomic, chemical and physical properties as atomic number increases
why does helium have the highest ionisation energy?
there is only one electron near the nucleus, so the attraction is very strong and there is no shielding present
why does first ionisation energy decrease down a group?
as you go down a group, one extra shell of electrons is added. this increases the distance from the nucleus and also increases shielding.
why does first ionisation energy increase across a period?
the number of protons (nuclear charge) increases, strengthening the attraction between electrons and nucleus, and pulling electrons closer.
the shielding stays the same in the same shell.
what is the electron configuration structure? (up to 6d)
1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d
how many electrons can a S orbital hold?
2
how many electrons can a P orbital hold?
6
how many electrons can a D orbital hold?
10
what is the shape of an S orbital?
spherical
what is the shape of a P orbital?
dumbbell shaped
why is there a drop from Mg to Al’s ionisation energy?
Al starts to fill a 3p subshell, while Mg’s electrons are still in 3s. This outer subshell is protected by shielding and also higher in energy.
why does atomic radius increase down a group?
an extra electron shell is added, increasing shielding, decreasing attraction
why does atomic radius decrease across a period?
nuclear charge increases - protons are being added
shielding stays constant - same shell
