Ionisation Energy

Question 1

What happens when you heat different elements?

Answer 1

They give out different distinctive colours.

Question 2

Analytical chemists can use these tests (color of flame) to identify the presence of an unknown element in a ________. The flame colors are due to the movement of electrons in the _____ ions when heated. The electrons in the ion _____ energy and move further away from the nucleus. When they return to its position closer to the nucleus, they release that energy in the form of _____ energy.

Answer 2

Ion
Metal
Gain
Light

Question 3

What does ground state mean?

Answer 3

Refers to electrons at the lowest energy level

Question 4

What does the term excited state mean?

Answer 4

Refers to the atom or ion once electrons have jumped to a higher energy level.

Question 5

The patterns of light emissions by electrons falling from their excited state to their ground state was studied by ______.

Answer 5

Bohr

Question 6

What is ionization energy?

Answer 6

Ionization energy is the amount of energy required to remove the outermost electron from a gaseous atom in its ground state.

Question 7

First ionization refers specifically to the removal of the first (______) electron while second ionization will be the energy required to remove the second electron.

Answer 7

Outermost

Question 8

Studies on electrostatics show us that the force between charged particles depends on the _______ of the respective charges as well as the distance between the charges. Ionization energy represents the energy required to ______ the attraction force between the nucleus of an atom and an electron of the same atom.

Answer 8

Magnitude

Overcome

Question 9

Factors affecting ionization include:(3)

Answer 9

• The greater the nuclear charge the stronger the nuclear attraction will be on the electron.
• The closer the electron is to the nucleus the stronger the nuclear attraction will be on the electron.
• The distance between the nucleus and the electron has a greater effect on the attraction force than the nuclear charge.

Question 10

What is nuclear charge?

Answer 10

The nuclear charge is the total charge of all the protons in the nucleus. It has the same value as the atomic number.

Question 11

What happens to the ionization energy when more and more electrons are removed? How do we understand this?

Answer 11

Increase in ionization energy. We can understand this when we consider that the relative nuclear attraction will become stronger as less electrons remain.

Question 12

Is the increase in ionization uniform. If not state why?

Answer 12

The increase is not uniform as all electrons are not at the same distance from the nucleus and the nuclear charge will be relatively stronger as the number of electrons decrease.

Question 13

Why is there a large increase to remove the second last electron?

Answer 13

This is because the last two electrons are closest to the nucleus in the same energy level called the first energy level.

Question 14

What can we conclude from the fact that there is a large increase in energy to remove the tenth and eighteenth electron from atoms of elements?

Answer 14

From this observation we can conclude that there are eight electrons in the second energy level and eight electrons in the third energy level.

Question 15

Trend down a group:

Answer 15

Ionization energy decreases down the group

Question 16

Trend down a group:

Answer 16

The ionization energy increases as you move across a period (left to right)

Question 17

Why does ionization energy decrease down the group?

Answer 17

The electrons are further away from the nucleus and thus easier to remove the outermost electron due to the weak nuclear attraction.

Question 18

What does ionization energy increase across a period?

Answer 18

The atomic radius decreases, the atom is smaller causing the outer electrons to be closer to the nucleus causing a stronger nuclear attraction.