Electrons, bonding and structure

Question 1

What is the characteristic shape of an s orbital?

Answer 1

Circular

Question 2

What is the shape of a p orbital?

Answer 2

3 figure 8’s on top of each other

Question 3

What are the levels of shells and orbitals and the number of electrons

Answer 3

1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d10

Question 4

Describe ionisation.

Answer 4

The removal of one or more electrons

Question 5

What is first ionisation energy?

Answer 5

The energy required to remove one electron from each atom in one mole of gaseous atoms to form one mole of gaseous 1+ ions

Question 6

Is ionisation endothermic r exothermic?

Answer 6

Endothermic, you have to put energy in.

Question 7

How would you write an equation for the first ionisation energy of oxygen?

Answer 7

O(g) ➡️ O+ (g) + e-

Question 8

How does nuclear charge affect ionisation?

Answer 8

The more protons there are in the nucleus, the more positively charged the nucleus is and the stronger the attraction for the electrons

Question 9

How does distance from the nucleus affect ionisation energy?

Answer 9

Attraction falls off very rapidly with distance. An electron close to the nucleus will be much more strongly attracted than one further away.

Question 10

How does shielding affect ionisation energy?

Answer 10

As the number of electrons between the outer electrons and the nucleus increases, the outer electrons feel less attraction towards the nuclear charge. This lessening of the pull of the nucleus by inner shells of electrons is called shielding.

Question 11

What is meant by saying something has a high ionisation energy?

Answer 11

There is a high attraction between the electron and the nucleus.

Question 12

What is the definition for the second ionisation energy?

Answer 12

The second ionisation energy is the energy needed to remove 1 electron from 1 mole of gaseous 1+ ions to form one mole of gaseous 2+ ions

Question 13

How do successive ionisation energies vary within each cell?

Answer 13

Within each cell, successive ionisation energies increase. This is because electrons are being removed from an increasingly positive ion. There is less repulsion amongst the remaining electrons, so they are held more strongly by the nucleus.

Question 14

What does a big jump on an ionisation energy graph signify?

Answer 14

A new shell being broken into, an electron is being removed from a shell closer to the nucleus

Question 15

How can you tell from an ionisation graph what group an element is from?

Answer 15

The number of electrons before the first big jump will indicate the group of the element.

Question 16

What causes ionic bonding?

Answer 16

Electrostatic attraction

Question 17

How are ions formed?

Answer 17

When an electron is transferred from one element to another

Question 18

Name four compound ions.

Answer 18

Nitrate - No3-
Carbonate - CO3(2-)
Sulfate - SO4(2-)
Ammonium
NH4+

Question 19

What is an ionic bond

Answer 19

An electrostatic attraction between two oppositely charged ions

Question 20

Give two examples of ionic compounds

Answer 20

Sodium chloride and magnesium oxide

Question 21

What kind of diagram do you use to show ionic compounds?

Answer 21

Dot and cross but with brackets around them to show the ionisation

Question 22

What is the structure of sodium chloride?

Answer 22

Giant ionic lattice

Question 23

Why is sodium chlorides structure a giant ionic lattice?

Answer 23

The ionic bonds are very strong so it takes a lot of energy to break up the lattice.

Question 24

Do ionic compounds conduct electricity? Why?

Answer 24

They do when they are molten or dissolved but not when they are solid

The ions in a liquid are free to move (and they carry a charge)
In a solid they are fixed in position by strong ionic bonds

Question 25

What is the melting point of ionic compounds? Why?

Answer 25

They have high melting points, the giant ionic lattices are held together by strong electrostatic forces. It takes loads of energy to overcome these forces, so melting points are very high.

Question 26

Are ionic compounds soluble?

Answer 26

Generally yes, water molecules are polar. Part of the molecule has a small negative charge, and the other bits have small positive charges. The water molecules pull the ions away from the lattice and cause it to dissolve.

Question 27

Describe covalent bonding

Answer 27

This is when atoms share electrons with one another so they’ve all go full outer shells.

Question 28

How are covalent bonds drawn?

Answer 28

Dot and cross diagrams

Question 29

Give two examples of giant covalent lattices

Answer 29

Diamond and graphite

Question 30

What is a giant covalent lattice?

Answer 30

Huge networks of covalently bonded atoms

Question 31

What kind of structure is diamond?

Answer 31

A giant covalent lattice, the hardest known substance

Question 32

What are the chemical properties of diamond? (5)

Answer 32

• very high melting point
• extremely hard
• vibrations travel easily through the stiff lattice so it’s a good thermal conductor
• it can’t conduct electricity - all the outer electrons are held in localised bonds
• it wound dissolve in any solvent

Question 33

How do the bonds in graphite affect the function?

Answer 33

• weak bonds between the layers in graphite are easily broken, so the sheets can slide over each other, graphite feels slippery and is used as a dry lubricant and in pencils

Question 34

What kind of bond is present in graphite?

Answer 34

Weak van der waals forces

Question 35

What is the structure of graphite?

Answer 35

Sheets of flat hexagons covalently bonded with three bonds each, fourth electron is delocalised and sheets are bonded together by weak van der waals

Question 36

How can electric current flow through graphte?

Answer 36

Delocalised electrons are t attached to any particular carbon atom and are free to move along the sheets, so an electric current can flow

Question 37

What is the melting point of graphite?

Answer 37

It is high because of the strong covalent bonds (over 3900k)

Question 38

Can graphite be dissolved in water?

Answer 38

No because the covalent bonds In the sheets are too difficult to break

Question 39

How are metals structured?

Answer 39

They exist as giant metallic lattice structures,
The electrons in the outermost shell of an atom are delocalised. Free to move about the metal. This leaves a positive metal ion. These are attracted to delocalised negative electrons. They form a lattice of closely packed positive ions in a sea of delocalised electrons.

Question 40

Describe the melting point of metals.

Answer 40

The number of delocalised electrons per atom affects the melting point. The more there are, the stronger the bonding so the higher the melting point. The size of the metal ion and the lattice structure also affect the melting point

Question 41

Describe the bonding in metals

Answer 41

There are no bonds holding specific ions together, the metal ions can slide past each other when the structure is pulled so metals are malleable and ductile.

Question 42

Are metals soluble?

Answer 42

No they are not, except for liquid metals because if the strength of the metallic bonds

Question 43

Can metals conduct heat and electricity?

Answer 43

Yes because the delocalised electrons can carry current and pass kinetic energy on

Question 44

Do shells have more energy if they are far away from the nucleus or close to it?

Answer 44

Further away from the nucleus