AS Flashcards
defn of isotopes
atoms of the same element with same number of protons but diff no. of neutrons
defn of relative isotopic mass
ratio of the mass of one atom of the isotope to 1/12 of the mass of an atom of carbon-12
angle of deflection
k(q/m), lower mass deflect more, lower charge deflect less
energy level diagram order
1s 2s 2p 3s 3p 3d 4s 4p 4d
exceptions for electronic configuration
Chromium
Expected: ..3d4 4s2(less stable deu to d orbital not filled up)
Actual: ..3d5 4s1(fuly filled up)
Copper
Expected: 3d9 4s2
Actual: 3d10 4s1
1st IE defn
Energy req to remove 1 mol of e from 1 mol of gaseous atoms of the element to form 1 mol of singly positively charged gaseous ions
2nd IE defn
Energy req to remove 1 mol of e from 1 mol of singly positively charged gaseous ions to form 1 mol of doubly positively charged gaseous ions
Nuclear charge defn
Electrostatic attraction b/w protons in nucleus of atom and surrounding electrons
Explain general increase in IE values WITHIN an element
-Since no. of protons remain constant, NC remains unchanged
-When electrons are removed, the increasingly positive ion attracts its remaining ve- more strongly, thus there is stronger electrostatic foa b/w nucleus and remaining electrons
-increasing amt of energy is required to remove each remaining ve-, resulting in successive IE increasing
Explain significant increase in value from 1st-2nd IE WITHIN an element
The 2nd IE involves the removal of a __electron from an inner shell that experiences a stronger electrostatic attraction with nucleus compared to the outermost __electron from 1st IE
-more energy is required to remove the __electron than the __electron, resulting in higher value of 2nd IE
Explain increase in 1st IE across periods
-Electrons are added to the same valence shell across periods, SE remains approx constant
-increase in NC outweighs negligible increase in SE
-ENC increases across period
-More energy is req to remove ve
Explain fall in atomic radius across periods
-Electrons are added to the same valence shell across periods, SE remains approx constant
-increase in NC outweighs negligible increase in SE
-ENC increases across period
-ve- are progressively pulled closer to nucleus
Explain 1st IE of Mg>Al
Smaller amt of energy is req to remove the 3p electron in Al which is of higher energy than the 3s electron in Mg
Explain 1st IE of P>S
There exists interelectronic repulsion between the paired 3p electrons in S
Smaller amt of energy is required to remove the 3p electron in S than the unpaired 3p electron in P
Explain significant drop in 1st IE after neon and argon
-valence elcerons of elements after Ne and Ar are present in shells of the next PQN and exp greater SE
-electrons further away from nucleus are less strongly attracted despite increase in NC
-less energy req to remove an electron from these elements
Explain fall in IE down the group
-no. of electron shells increase down the group, leading to increasing SE
-valence elcerons are increasingly further away from nucleus and are less strongly attracted to nucleus despite the increase in NC
-less amt of energy is req to remove the valence electron
Explain rise in AR down the group
-no. of electron shells increase down the group, leading to increasing SE
-valence elcerons are increasingly further away from nucleus and are less strongly attracted to nucleus despite the increase in NC
-hence valence electrons are increasingly further away from the nucleus despite the increase in NC
-hence AR increases down the group
Why are group 1 metals more readily oxidised and increases in reactivity down the group?
-no. of electron shells increase down the group, leading to increasing SE
-valence elcerons are increasingly further away from nucleus and are less strongly attracted to nucleus despite the increase in NC
-less amt of energy is req to remove the valence electron
-more reactive
Determine group from IE data(within an element)
Given that the largest increase in IE is found between the __ and __ IE, the __electron is removed from an inner shell while the __electron is removed from the valence shell, thus the element has __ valence electrons and belongs to Group __
Why does Helium have a much higher IE than Hydrogen?
Helium has alot more protons than hydrogen, resulting in higher NC while SE for He and H remain approximately similar, the ENC of He is higher than that of H, therefore larger amounts of energy is required to remove electron
Why is Grp 1’s cation radii smaller than its atom
When the s electron is removed from the valence shell of Grp 1 element, there is now 1 less electron shell, therefore since they have the same number of protons, nuclear charge remains constant, thus larger amounts of energy is required to remove the higher ENC of cation, hence valence electrons are pulled closer to the nucleus, resulting in a smaller radius
Why IE lower when it is supp to be higher(explain using NC)
__ has a lower NC than __
electrons are removed from the saem orbital, thus SE remains approx constant, hence ENC is lower
Weaker efoa b/w nucleus and ve- result in less energy required to remove the ve- in the __orbital for __ compared to_
How to draw successive IE’s in graph
General increase, if grp 15-5ve-, so draw sharp jump from 5th to 6th electron
Explain why diff b/w 2 IE’s is only 10kJ/mol(for element with larger NC AND SE)
The valence electrons of __ are of higher energy. However, significant increase in NC(more protons) would suggest a much higher IE. However, there are also greater no. of inner electrons of __, hence the SE is expected to increase significantly to counterbalance the increase in NC
