3.1.1 atomic structure Flashcards
history of the atom
lol
what happens when an e- gains/loses energy
when an e- gains energy it gets excited and moves to a higher energy level. when it loses energy it relaxes to its ground state
anion
-ve ion
cation
+ve ion
isotope
atom of an element with the same number of protons and a different number of neutrons
(you can have ions of isotopes)
why do isotopes of they same element have the same chemical properties
because they have the same electron configuration/ number of e-
why do isotopes of the same element have different physical properties
bc they each have a different number of neutrons.
isotopes with more neutrons have
1. higher mass
2. higher density
3. higher m/b points
4. slower diffusion rates
relative atomic mass
how is it calculated
average mass of an atom of an element to 1/12 the mass of a C12 atom
using abundance of isotopes
what is an energy level
specific orbits which electrons occupy as they orbit around the nucleus
each energy level represents a specific energy value
each energy level contains a different number of electrons
as you go further out energy values are higher
what is a sublevel
energy levels can be broken down into sublevels: s, p, d etc.
energy level one only has s
el 2 has s and p
el 3 has s, p, d
what is an orbital
sublevels can be broken down into orbitals. these are basically areas where electrons probably occupy. there are max 2 electrons in each orbital
the s sublevel has 1 orbital, so 2 e-
the p sublevel has 3 orbitals; 6
the d sublevel has 5 orbitals; 10
why does 4s fill before 3d
as we go further out from the nucleus the sublevels overlap more and more. 4s is actually of lower energy than 3d. according do Aufbau principle, electrons fill the lowest energy orbitals. once it fills it’s of higher energy.
the diagonal rule can be used to identify which sublevels come next
two types of representing electron configuration
standard
and short structure, where you use the nearest noble gas in square brackets then add the extra e-
what are two special cases of e- configuration
chromium
copper
special case of chromium
should be the standard configuration but instead it ends in
4s13d5
because electron is demoted from 4s to 3d because atoms are more stable with a half set of orbitals
special case of copper
should be the standard configuration but instead it ends in
4s13d10
because electron is demoted from 4s to 3d as the atom is more stable with a full set of 3d orbitals
ionisation energy
energy required to remove one mole of electrons from one mole of atoms in gaseous state
units of IE
KJmol^-1
why is the reaction of IE endothermic
energy needs to be taken in by the outer e- being removed to overcome the eFoA between the nucleus and itself
def 2nd IE
energy required to remove one mole of electrons from +1 ions (!!) in a gaseous state
how can we quickly form the IE equation for different IEs?
nth IE ;
then the product of the reaction is +n charge
why is 1st IE the lowest value always
eFoA is stronger in +ve ions compared to a less positive or neutral atom because there is more positive acting on the outer e-
each time requires more energy; you’re trying to remove from an increasingly +ve ion
what are successive ionisation energies
they are the IEs (in KJmol^-1) to remove successive electrons from the same atom
results can be logged on a graph and conclusions have been made for it
what can be observed from a graph depicting successive IEs?
- different electrons require different amounts of energy to be removed
- graph is not linear
- jumps in the graph (indicate energy levels)
