module 3 - periodic table and energy Flashcards
what columns make up the S block
the two leftmost columns,
note - helium is also an S block element because it has the electron configuration 1s2
where is the P block on the periodic table?
the six rightmost columns
called p-block because elements in the p block have a partially filled p sub-shell
where is the d block on the periodic table?
lies between the s and p blocks, elements are often transition metals
where is the f block in the periodic table
what are the elements in these blocks referred to?
detached along the bottom of the table.
elements have a partially filled F sub-shell
elements referred to as the lanthanides and actinides (top and bottom row)
which element is an s block element that does NOT sit on the left-hand side?
helium
define first ionisation energy
the energy required to remove and electron from every atom in a mole of atomic gas, to produce a mole of unipositive gaseous ions
what is the second ionisation energy
the energy required to remove an electron from every ion in a mole of unipositive gaseous ions to produce a mole of dipositive gaseous ions
what is the equation for ionisation energy in terms of n
X^(n-1) + energy –> e- + X^n+
in ionisation equations, what state symbol do all the atoms/ ions have?
g (gas)
what factors effect ionisation energies
nuclear charge - the number of protons in the nucleus - the more protons, the greater the ionisation energy
distance from nucleus - less energy needed to remove electrons that are further away
shielding - greater the number of electrons, the lower the ionisation energy
what is the pattern for increasing ionisation energies
the n=1 shell has a higher ionisation energy than the n=2 shell.
within the n=2 shell, successive ionisation energies will rise as the ion becomes more positively charged
what is the lowest ionisation energy of sodium
first ionisation energy
break down the trend of the sodium atom
electron configuration = 1s2 2s2 2p6 3s1
first ionisation energy corresponds to the removal of an electron from the n=3 shell
the second ionisation energy corresponds to the removal of an electron from the n=2 shell
between the third and ninth ionisation energies, an electron is being removed from the n=2 shell of an increasingly positive ion
its tenth ionisation energy corresponds to the removal of an electron from the n=1 shell
what is the ionisation energy trend across a period
first ionisation energy increases across a period
because the atomic radius decreases, proton number increases across a period so electrons are more attracted to the nucleus. nuclear charge increases across a period
what trends do ionisation energies follow down a group
first ionisation energy decreases down a group because atomic radius increases
more electrons between the nucleus, so experiences lower attraction
what would you see when magnesium solid reacts with an excess of dilute HCl
you would see rapid bubbles/ effervescence and the magnesium would dissolve
write the ionic equation for the reaction of magnesium and hydrochloric acid
Mg(s) + 2H^+(aq) –> Mg^2(aq)+ H2(g)
describe the trend in ionisation energy down group 2
ionisation energy decreases as you go down as electron shielding increases, increasing the atomic radii and making the valence electrons less attracted to the positive nucleus. therefore easier to lose an electron
why is the second ionisation energy higher than the first?
because the second ionisation energy removes an electron from a positive (1+) ion, which has increased nuclear charge, so less easy to lose an electron
why does Al have a higher boiling point than Mg
because Al has a higher atomic number and therefore more electrons, increasing the electrostatic attraction between the delocalised electrons and nucleus. Al forms 3+ ions whereas Mg forms 2+ ions, therefore the bond energy is higher in Al
