Chapter 3 - Bonding

Question 1

What is ionic bonding

Answer 1

ionic bonding occurs when electrons are transferred from the metal to the non-metal to achieve full outer shells.
This creates electrostatic forces of attraction between the atoms forming an ionic compound.

Question 2

What are the physical properties of ionic compounds

Answer 2

high electrostatic forces of attraction causing a high melting and boiling points

soluble in polar solvents such as water as the water molecules can orient themselves around the polar atoms causing ionic compounds to dissolve as the charge increases the solubility decreases as the polar solvent cannot overcome the electrostatic forces of attraction

cannot conduct electricity in a solid as the ions cannot move

Question 3

How do covalent bonds hold an atom together

Answer 3

There is electrostatic forces of attraction between the electrons and the nucleus

Question 4

What is dative covalent bonding

Answer 4

When the shared pair of electrons comes from only one of the bonding atoms

e.g. NH4+ H3O+ NH3BF3

This does not affect the shape of the molecule

Question 5

What is electronegativity

Answer 5

electronegativity is the power of an atom to attract the electron density in a covalent bond towards itself

Question 6

What factors does electronegativity depend on

Answer 6

the nuclear charge
distance between the nucleus and the outermost electron the shielding of the nuclear charge and the outermost electron

The smaller the atom the greater the closer the shared electron is to the nucleus so the greater the electronegativity

The larger the nuclear charge with the same amount of shielding the greater the electronegativity

Question 7

diagram showing electronegativity

Answer 7

Question 8

what is a polar bond

Answer 8

When there is an unequal sharing of electrons between the atoms that are bonded together covalently

Question 9

What causes a polar bond to occur

Answer 9

The difference in electronegativity of the two atoms that are covalently bonded together

Question 10

What is a permanent dipole

Answer 10

The sum of the effect of all the polarity of all the bonds in a molecule. If the effects of the polar bonds cancel the molecule will not be a permanent dipole however it will still have polar bonds.

Question 11

What are the three types of intermolecular forces

Answer 11

Van der Waals
Dipole-Dipole
Hydrogen bonding

Question 12

What s metallic bonding

Answer 12

Metallic bonding is the electrostatic forces of attraction between the positive metal ions and the delocalised electrons

Question 13

What are the factors that affect the strength of metallic bonding

Answer 13

1. Number of protons/ strength of nuclear attraction
   The more protons the stronger the bond
2. Number of delocalised electrons per atom (the outer shell electrons are delocalised)
   The more delocalised electrons the stronger the bond
3. The size of the ion
   The smaller the ion the stronger the bond

Question 14

the types of bonding and its strucutres

Answer 14

Question 15

properties of the types of bonding

Answer 15

Question 16

Shapes of molecules:

Linear
Trigonal planar
Tetrahedral
Trigonal pyramid
Bent
Trigonal bipyramid
Octahedral

bonding pairs
Lone pairs
diagram
Bond angle
Examples

Answer 16

Question 17

What are the steps in explaining the shapes of molecules

Answer 17

Question 18

What does a lone pair of electrons do the bonds angle

Answer 18

reduces bond angle by 2.5 degrees

Question 19

What are Van der Walls forces

Answer 19

These are sometimes called induced dipole-dipole interactions and occur between simple covalent molecules and the separate atoms in noble gasses.

Electrons are constantly moving in random directions and at any point in time the pair of electrons could be situated closer to one part of the molecule causing that side to become partially negative in that instance of time