Atomic Structure

Question 1

What is an orbital?

Answer 1

A region that can hold up to two electrons with opposite spins

Question 2

What is the shape of an s-orbital?

Answer 2

Spherical

Question 3

What is the Shape of a p-orbital?

Answer 3

Dumbell

Question 4

What is the first ionisation energy?

Answer 4

Is the enthalpy change when ONE MOLE of electrons is removed from ONE MOLE of gaseous atoms to form ONE MOLE of gaseous positive ions

Question 5

What is the successive ionisation energy?

Answer 5

Successive ionisation energies are a measure of the energy required to remove each electron in turn from an atom

Question 6

What is Aufbau Principle?

Answer 6

Electrons will fill lower energy orbitals before higher energy ones

Question 7

What is the Pauli Exclusion Principle?

Answer 7

No to electrons can have the same four quantum numbers. The means that electrons in the same orbital have opposite spins

Question 8

What is Hund’s rule?

Answer 8

Every orbital in a sub shell (s,p,d,f) is singly occupied before any orbital is doubly occupied. Electrons in singly occupied orbitals will have the same spin.

Question 9

What is the difference between shells, sub shells and orbitals?

Answer 9

• Shells are the principle quantum number/ energy level (1,2,3 or 4)
• A sub shell is what each shell is split into: s,p,d,f and with each shell you gain a sub shell
• Orbitals are regions that can hold up to tow electrons with opposite spins so:
  1. The s subshell has 1 orbital and so can hold 2 electrons
  2. The p sub shell has 3 orbitals and so can hold 6 electrons
  3. The d sub shell has 5 orbitals and so can hold 10 electrons
  4. The f sub shell has 7 orbitals and so can hold 14 electrons
• Only 2 electrons max. can be in a orbital!

Question 10

What factors affect ionisation energy?

Answer 10

1. Distance from the nucleus
2. Nuclear Charge
3. Shielding
4. Charge on ion

Question 11

What is an isotope?

Answer 11

Isotopes are atoms of the same element with different numbers of neutrons and therefore different mass numbers. The atomic number remains the same

Question 12

What is the relative isotopic mass?

Answer 12

The mass of an isotope relative to 1/12th of the mass of an atom of carbon-12

Question 13

What is the relative atomic mass?

Answer 13

The man mass of an element relative to 1/12th the mass of an atom of carbon-12

Question 14

What is the relative molecular mass?

Answer 14

The sum of the relative atomic masses in simple covalent molecules and diatomic elements e.g. nitrogen (N2)

Question 15

What is the relative formula mass?

Answer 15

The sum of the relative atomic masses in compounds with giant structures e.g. sodium chloride

Question 16

Why are the second ionisation energies of calcium and strontium greater than their first ionisation energies?

Answer 16

Removing an electron from a more positive ion

Question 17

Why do successive ionisation energies increase with ionisation number?

Answer 17

1. Radius decreases

2. Attraction between (the remaining) electron and nucleus increases

Question 18

How do the first ionisation energies of Mg (738) and Al (578) show details of electron structure?

Answer 18

1. Mg has oute electron in 3s sub shell
2. Al has outer electron in 3p sub shell
3. 3p subshell has higher energy than 3s sub shell