ionization energies

Question 1

explain ionization energy

Answer 1

electrons can be removed from atoms and the energy it takes to remove them can be measured

this is called ionisation energy because as the electrons are removed the atoms become positive ions

Question 2

define ionisation energy

Answer 2

ionisation energy is the energies required to remove the electrons one by one from an atom in the gaseous state

Question 3

define the first ionisation energiy

Answer 3

the first electron needs the least energy to remove it because it is being removed from a neutral atom

Question 4

define the second ionisation energy

Answer 4

the second electron needs more eergy than the first because it is being removed from a 1+ ion

Question 5

define the third ionisation

Answer 5

the third electron needs even more energy to remove it because it is being removed from a 2+ ion

Question 6

what information does the trends in the first ionisation energies give

Answer 6

the trends in the first ionisation energies moving across a period in the periodic table can also give informatio about the energies of electrons in main levels and sub-levels

Question 7

why do ionization energies increase

Answer 7

ionisation energies generally increase across a period because the nuclear charge is increasing and this makes it more difficult to remove the electrons

Question 8

despite an increase in nuclear charge what makes it easier to remove electrons

Answer 8

the repulsion between these paired electrons make it easier to remove one of them, despite the increase in nuclear charge

Question 9

why is their a general decrease ion first ionisation energy going down the group

Answer 9

this is because the outer electron is in a main level that gets further from the nucleus in each case.

Question 10

whaty happens when the nuclear charge increase going down the group

Answer 10

the positive charge felt by an electron in the outer shell is less than the full nuclear charge.

this is because of the effect of the inner electrons sheilding the nuclear charge

Question 11

what factors affect ionisation energy

Answer 11

nuclear charge

distance from nucleus

shielding

Question 12

explain how nuclear charge affects ionisation energy

Answer 12

the more protons there are in the nucleus, the more positively charged the nucleus is and the stronger the attraction for the electrons

Question 13

explain how the distance from the nucleus affects ionisation energy

Answer 13

attraction falls off very rapidly with distance

an electron close to the nucleus will be much more strongly attracted than one further away

Question 14

explain how shielding affects ionisation energies

Answer 14

As the number of electrons between the outer electrons and the nucleus increases, the outer electrons feel less attraction towards the nuclear charge

this lessening of the pull of the nucleus by inner shells of electrons is called sheilding

Question 15

define successive ionisation energies

Answer 15

each time you remove an electron there’s a successive ionisation energy

Question 16

define high ionization energy

Answer 16

a high ionisation energy means there’s a high attraction between the electron and the nucleus and so more energy is needed to remove the electron

Question 17

what does a graph of successive ionization energies do

Answer 17

provides evidence for the shell structure of atoms

Question 18

what happens within each shell

Answer 18

within each shell successive ionization energies increase.

this is because electrons are being removed from an increasingly positive ion

there’s less repulsion amongst the remaining electrons, so they’re held more strongly by the nucleus

Question 19

when do the bug jumps happen in ionization energy

Answer 19

the big jumps happen when a new shell is broken into

an electron is being removed from a shell closer to the nuclues

Question 20

what are the trends in the first ionization energies

Answer 20

the first ionization energies of elements down a group of the periodic table decrease

the first ionization energies of elements across a period generally increase

Question 21

explain why the first ionization energies of elements down a group decrease

Answer 21

if each element down the group has an extra electron shell compared to the one above, the extra inner shells will shield the outer electrons from the attraction of the nucleus

also, the extra shell means that the outer electrons are further away from the nucleus, so the nucleus’s attraction will be greatly reduced

these factors make it easier to remove outer electrons, resulting in a lower ionization energy

Question 22

explain why ionisation energies increases across a period

Answer 22

the number of protons is increasing, which means a stronger nuclear attraction

all the extra electrons are at roughly the same energy level even if the outer electrons are in different orbital types

so there’s little extra shielding effect or extra distance to reduce the attraction to the nucleus

Question 23

explain how the sub shell structure creates a drop between groups 2 and 3

using aluminum and magnesium as examples

Answer 23

aluminum outer electron is in a 3p orbital rather than a 3s.

the 3p orbital has slightly higher energy than the 3s orbital, so the electron is, on average, to be found further from the nucleus

the 3p orbital has additional shielding provided by the 3s2 electrons

both of these factors are strong enough to override the effect of the increased nuclear charge, resulting in the ionization energy dropping slightly

Question 24

what does the pattern in ionization energies provide

Answer 24

provides evidence fro the theory of electron sub-shells

Question 25

why is there a drop between groups 5 and 6

Answer 25

electron repulsion

Question 26

explain the drop between groups 5 and 6

Answer 26

the shielding is identical in the phosphorus and sulfur atoms, and the electron is being removed from an identical orbital

in the phosphorus case, the electron is being removed from a singly occupied orbital

but in sulfur, the electron is removed from an orbital containing two electrons

the repulsion between two electrons in an orbital means that electrons are easier to remove from shared orbitals