Ionisation - Ionisation Energies.

Question 0

How can an atom become ionised

Answer 0

It requires sufficient energy of the right frequency which when absorbed allows an electron to move so quickly that it can escape the pull of its nucleus.

Question 1

What happens when an atoms absorb energy.

Answer 1

Both themselves and their electrons move faster.

Question 2

What is molar ionisation energy?

Answer 2

The energy required to remove one mole of electrons from one mole of atoms in the gas phase at 295K and 1 atmosphere pressure.

Question 3

What information do successive ionisation energy plots give?

Answer 3

They give information about the arrangement of electrons in the atom.

Question 4

What is an orbital?

Answer 4

An orbital is a volume of space where there is a high probability of finding an electron.

Question 5

What are orbitals grouped into?

Answer 5

Subshells and quantum shells.

Question 6

How many electrons are held in the first quantum shell?

Answer 6

2

Question 7

How many electrons are held in the second quantum shell?

Answer 7

8

Question 8

How many electrons are held in the third quantum shell?

Answer 8

18 (This includes the elements of the first line of the D block.)

Question 9

How many orbitals does an “S” subshell have? And how many electrons can it hold?

Answer 9

An S subshell contains 1 orbital and can contain 2 electrons.

Question 10

How many orbitals does a “P” subshell have? And how many electrons can it hold?

Answer 10

Three orbitals, holding 6 electrons; two each with opposite spins.

Question 11

How many orbitals does a “D” subshell have? And how many electrons can it hold?

Answer 11

It has five orbitals, each holding 2 electrons with opposite spins. (10 electrons total)

Question 12

Considering the ionisation energy of the first 12 successive elements, explain the big increase in I.E between Hydrogen and Helium.

Answer 12

This is due to the increase (double) in the number of protons in the nucleus. This number would actually be larger if electrons didn’t repel each other.

Question 13

Considering the ionisation energy of the first 12 successive elements, explain the big drop in IE between helium and lithium.

Answer 13

This is due to the electrons of the 1S shell partly shielding the electrons in the 2S shell from the pull of the nucleus.

Question 14

Considering the ionisation energy of the first 12 successive elements, explain the increase in I.E between lithium and beryllium.

Answer 14

This is due to the increase in effective nuclear charge as there are now more protons.

Question 15

Considering the ionisation energy of the first 12 successive elements, explain the small decrease in I.E between beryllium and boron.

Answer 15

This is due to the 1S and 2S orbitals partly shielding the electrons in the 2P orbital of boron.

Question 16

Considering the ionisation energy of the first 12 successive elements, explain the increase in I.E between Boron and Nitrogen (carbon between).

Answer 16

An increase in Effective nuclear charge due to the addition of protons to the nucleus.

Question 17

Considering the ionisation energy of the first 12 successive elements, explain the decrease in I.E between Nitrogen and Oxygen.

Answer 17

The 2P us she’ll is half full when nitrogen is reached. Th new electron has to occupy the orbital which already has an electron in it. The repulsion between these two electrons causes the I.E to decrease.

Question 18

Considering the ionisation energy of the first 12 successive elements, explain the increase in I.E between Oxygen and Neon (fluorine between).

Answer 18

Further increases in effective nuclear charge due to the addition of still more protons.

Question 19

Considering the ionisation energy of the first 12 successive elements, explain the sharp drop between Neon and Sodium.

Answer 19

This is due to the new electron going into a new shell and the screening that results from the 2P electrons.

Question 20

Considering the ionisation energy of the first 12 successive elements, explain the increase in I.E between Sodium and Nitrogen.

Answer 20

An increase In Effective Nuclear Charge.

Question 21

Why is the log of the I.E taken when considering the successive I.E of Sodium?

Answer 21

Because of the very large energy jumps between each quantum shell.

Question 22

Explain the trend seen of the successive ionisation energies of Sodium.

Answer 22

One electron needs very little energy to remove it as it is in a high energy level to begin with. 8 electrons required considerably more energy and as such are at a lower energy level. Similarly two electrons were in a lower energy level still and required the most energy to remove.

Question 23

What is the shape of an “S” orbital.

Answer 23

It is spherical.

Question 24

What is the shape of a “P” orbital?

Answer 24

Dumbbell shaped with the three orbitals mutually at right angles.

Question 25

State the order in which subshells are filled.

Answer 25

1S 2S 2P 3S 3P 4S 3D.

Question 26

What are the two exceptions to the electronic configuration of elements 1-36?

Answer 26

Copper and chromium.

Question 27

What are these exceptions due to?

Answer 27

A orbital being more stable when half full than when partly or nearly full.