Chapter 5 Electrons and Bonding

Question 1

How are shell numbers and energy related? What is n?

Answer 1

As the shell number increases, the energy of the shell increases.
The shell number is n, the principal quantum number

Question 2

What are atomic orbitals?

Answer 2

Regions of space around the nucleus which can hold up to two electron of opposite spin

Question 3

What are electrons?

Answer 3

Clouds of negative charge

Question 4

What are shells made of? What are sub shells?

Answer 4

Shells are made of sub shells
Sub shells are made of the same type of orbital grouped together, 3d sub shell contains 5 d orbitals

Question 5

What is the shape of S orbitals? How many does each shell have?

Answer 5

Spherical shaped
Each shell has 1 s orbital

Question 6

What is the shape of the p orbital? How many p orbitals does each shell have?

Answer 6

Dumbbell shaped. One in the x, y, and z axis.
After the second shell (inclusive of the second), each shell has 3 p orbitals

Question 7

How many d and f orbitals does each shell have?

Answer 7

At the 3rd shell and above, each shell has 5 d orbitals each, with the d sub shell holding up to 10 electrons
At the 4th shell and above, each shell has 7 orbitals each, with the f sub shell able to hold up to 14 electrons

Question 8

How do orbitals fill?

Answer 8

The lowest energy orbital fills first. If a sub shell is present, meaning all orbitals are at the same energy level, each one is singly occupied first, before pairing begins

Question 9

What is the sequence of orbitals filling?

Answer 9

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4s, 4p

Question 10

How is the electron configuration written? How does orbital filling relate?

Answer 10

In terms of sub shells, with the number of electron filled in superscript.
Even though the 4s sub shell fills first, the 3d sub shell should be written before the 4s

Question 11

How do sub shells empty? What is an important note about this rule?

Answer 11

Highest energy fills first
The 4s sub shell empties first, as the 3d sub shell has a lower energy than the 4s when filled. This explains why most transition metals have at least a +2 ion

Question 12

What is the electron configuration of Bromine? What is the shorthand configuration? Atomic number 35

Answer 12

1s2, 2s2, 2p6, 3s2, 3p6, 3d10, 4s2, 4p5
[Ar] 3d10, 4s2, 4p5

Question 13

How do you write the shorthand configuration of electrons?

Answer 13

Find the noble gas for the element in question before it. Must be before.
Write the noble gas in square brackets, continue the electron configuration from after the noble gas

Question 14

What are the two exceptions to electron configuration and what is their configuration?

Answer 14

Chromium 1s2, 2s2, 2p6, 3s2, 3p6, 3d5, 4s1
Copper 1s2, 2s2, 2p6, 3s2, 3p6, 3d10, 4s1

Question 15

Why is lithium called an s block element?

Answer 15

It’s highest energy electron/ sub shell is (in) the s orbital

Question 16

Define ionic bonding

Answer 16

The strong electrostatic force of attraction between anions and cations

Question 17

What is a giant ionic lattice?

Answer 17

Repeating, regular arrangement of oppositely charged ions, with the attraction in all directions

Question 18

Why do ionic compounds have very high melting points? What factors affect the strength of an ionic compound?

Answer 18

Ionic compounds are in a giant ionic lattice. Lots of energy is needed to overcome the many ionic bonds, the strong electrostatic force of attraction between oppositely charged ions, giving a high boiling boing
The great the charge of the ions, the greater the attraction between the ions, and the greater
the melting point/ energy to overcome
Also atom size

Question 19

What happens when an ionic compound dissolves?

Answer 19

The ionic lattice breaks down. The water surrounds the ions
The stronger the charges, the greater the ionic bonds, more energy needed to overcome, them, so lower solubility.

Question 20

How is electrical conductivity differ with ionic compounds?

Answer 20

In solids, the oppositely charged ions are in fixed positions, unable to more and carry charge
In aqueous / molten, the ions are free to move, so can move and carry charge, acting as mobile charge carriers, conducting electricity

Question 21

What factor does solubility depend upon?

Answer 21

Whether the interactions between the solvent and ionic compound is greater than the strength of the ionic lattice

Question 22

Define a covalent bond

Answer 22

The strong electrostatic force of attraction between a shared pair of electrons and the nuclei of the bonded atoms

Question 23

Compare the location of attraction with ionic compounds and covalent bonds?

Answer 23

In ionic, the attraction is in all directions in 3 dimensions
In covalent, the attraction is localised, based solely between the shared pair of electrons and the nuclei of the bonded atoms

Question 24

How many covalent bonds can form?

Answer 24

Usually, the bonded atoms will aim to have the same electron configuration as the nearest noble gas
There are exceptions, including expanding the octet, BF3
After period 3, inclusive, d sub shell becomes available so can form as many covalent bonds as the number of electrons in the outer shell

Question 25

What is a dative covalent bond?

Answer 25

A covalent bond where the shared pair of electrons have been donated by only one of the bonded atoms