Intro to Bonding

Question 1

First Ionisation Energy and Electronegativity

Answer 1

First ionization energy is the energy required to remove one electron from one mole of the atom in its gaseous state. Electronegativity is the ability of an atom to attract electrons.

Question 2

Why does F form F- ions?

Answer 2

Due to its high electronegativity and high first ionization energy, F attracts electrons and produces anions. However it can only produced F- ions because any extra electrons would go into the next energy level with extra shielding and this is not favourable. Electron shielding is when the outer electrons experience a reduced attractive force as inner electrons shield the outer electrons from the nucleus.

Question 3

Transition Metals

Answer 3

Transition metals have low first ionization energies, so they form cations.

Question 4

Valency

Answer 4

Valency tells us how atoms of an element will combine with other atoms. Usually related to the number of H2 of Cl2 atoms that the element can combine with.

Question 5

Lewis Structure - Electron dot diagrams

Answer 5

Lewis diagrams are a method of showing how the electrons are arranged in ions and covalent molecules, including bonding electrons and lone pairs. They can be used to determine if it is a single, double or triple bond.

1. only show valence electrons
2. electrons always arranged in pairs
3. shared pair of electrons (bonding pair) should be clearly between the two atoms
4. non-bonding electrons should be isolated on one atom.

Question 6

Steps for Lewis Structure

Answer 6

1. Determine how many valence electrons there are in the ion.
2. Draw the element symbol.
3. Arrange the valence electrons around the symbol in pairs
4. As it is an ion, place square brakcets around the structure and place a charge.

Question 7

Lewis structures for molecules

Answer 7

1. Determine how many valence electrons there are in each atom.
2. If there are more than two atoms, place the atom with the highest valency in the centre and the other atoms around it.
3. Arrange the electrons around the atoms so that each atom ends up with the correct number of electrons (takes practice).
4. Check that your final structure has the correct number of electrons overall and that each atom has the correct number of electrons.

Question 8

Valency Explained

Answer 8

Valency is a measure of an element’s combining capacity with other atoms when it forms chemical compounds or molecules. We determine valency by finding the number of hydrogen of chlorine atoms that can bond to that element.

Question 9

Lewis Strucutres for polyatomic ions

Answer 9

1. Determine how many valence electrons in each atom.
2. Use charge to determine if there are extra electrons or fewer.
3. If there are more than two atoms, place the atom with the highest valency in centre.
4. Arrange electrons around the atoms so correct electrons occur.
5. Place square bracket around your structure and put the charger in the upper right corner outside the bracket.
6. Check overall.