TOPIC 1: Atomic structure and the Periodic Table

Question 1

What is the charge and mass of a proton?

Answer 1

Charge = 1+
Mass = 1

Question 2

What is the charge and mass of a neutron?

Answer 2

Charge = 0
Mass = 1

Question 3

What is the charge and mass of a electron?

Answer 3

Charge = 1-
Mass = 1/1837

Question 4

Where are protons and neutrons located?

Answer 4

In the nucleus of an atom.

Question 5

Where are electrons located?

Answer 5

They are contained in orbitals which are found in different energy levels.

Question 6

What are orbitals?

Answer 6

An area where electrons are likely to be found.

Question 7

What are some rules assossiated with electron orbitals?

Answer 7

1. The order in which orbitals are filed up and written is least energy to most energy
2. Order of energy levels is S,P,D,F
3. Only one orbital in the first quantum shell
4. Electrons in the second sub-shell (2S and 2P) can hold up to 8 electrons total (2 in S orbital and 6 in P orbital). P orbital is divided into 3 smaller orbitals (Px, Py and Pz orbitals). They all have a shape like the number 8.
5. The third shell is divided into 3s, 3p, 3d orbitals. The 3d orbital has more energy than the 4s orbital, so it comes after the 4s orbital.

Question 8

What are the exceptions to the rule that the 4s orbital must come before the 3d orbital?

Answer 8

The only exception is when writing the electronic configuration of Copper and Chromium.

Question 9

Why are copper and chromium exceptions to the electron orbital rule?

Answer 9

As it is more stable for the atom as the d shell is either half filled or fully filled as the 4s orbital will lose an electron to fill the 3d shell.

Question 10

What is Hund’s rule?

Answer 10

Each orbital mist be filled with one electron before pairing electrons up.

Question 11

What is Pauli’s exclusion principle?

Answer 11

No two electrons can be identical, so electrons have different spins (Spin up and Spin down electrons).

Question 12

What is periodicity?

Answer 12

A trend of repeating patterns you see across a period.

Question 13

What is first ionization energy?

Answer 13

The energy required to remove one mol of electrons from one mol of gaseous atoms making one mol of gaseous positive ions.

Question 14

How does the location of the outer electron affect first ionization energy?

Answer 14

The closer the outer electron is to the nucleus, the higher the first ionization energy as electrostatic forces of attraction are higher.

Question 15

What is the equation for ionization energy?

Answer 15

Ionization energy = energy of electron when removed - initial energy of electrons.

Question 16

How does ionization energy change across a period?

Answer 16

As you go across a period, the number of protons increases therefore nuclear charge increases which leads to stronger intermolecular forces of attraction so first ionization energy increases. As we are in the same period, we have the same number of electron shells so same level of shielding.

Question 17

How does ionization energy change down a group?

Answer 17

Number of energy levels increases so they are further away from the nucleus and experience less electrostatic forces of attraction so first ionization energy decreases.There is also more energy levels so increased electron shielding so electrons can escape easier.

Question 18

What groups have an exception to the first ionization energy trend?

Answer 18

Group 3 and Group 6.

Question 19

Why is group 3 an exception to the first ionization energy rule?

Answer 19

When you get to group 3, you enter a new quantum shell so ionization level decreases.

Question 20

Why is group 6 an exception to the first ionization energy rule?

Answer 20

The 3p energy level is getting into pairs so we see a massive electron repulsion force so first ionization level decreases as it is easier for electrons to escape.

Question 21

What are isotopes?

Answer 21

Atoms with the sam amount of protons but different amount of neutrons.

Question 22

What is relative atomic mass?

Answer 22

The weighted mean mass of an elements atoms compared to 1/12th of Carbon 12.

Question 23

What is relative isotopic mass?

Answer 23

The weighted mean mass of an elements isotopes compared to 1/12th of Carbon 12.

Question 24

What is abundance?

Answer 24

The amount of wanted atoms in a total mixture of atoms.

Question 25

What are the steps for Mass Spectrometry?

Answer 25

1. Place your element in the sample chamber
2. The atom will go through ionization and will lose an electron, making it a positive ion. This happens because it is bombarded with a high energy beam which knocks off an electron.
3. The atom is now attracted to a negatively charged plate, which leads the ions to accelerate towards the plate
4. All of the ions have the same KE.
5. Once passing the negatively charged plate, they stop accelerating and start ion drift. This is where the ions drift to the end of the machine.
6. The lighter ions drift faster and reach the end faster.
7. An electromagnet changes the direction of the drift of the electrons to a side.
8. The one with the smallest weight will curve the most and touch the side, where it gets detected.
9. Once ions reach the end, ion detection takes place which leads to them gaining an electron which creates a current.

Question 26

What conditions are required in order for a Mass Spectrometry to be done correctly?

Answer 26

The mass spectrometer must be in a vacuum to avoid air molecules from colliding with the wanted isotopes.

Question 27

How do you interpret the results from a Mass Spectrometry?

Answer 27

• Points reached in the machine explain the mass of the atom.
• Current produced is used to find the abundance of an isotope.