Ions and bonds

Question 1

Primary bond

Answer 1

formed between oppositely charged ions due to mutual electrostatic - ionic bonding

Question 2

Lattices

Answer 2

of undefined number of ions

Question 3

Cations

Answer 3

= loose the electrons in the valence shell -> smaller in radius than its atom

Question 4

Anions

Answer 4

= gain electrons, which means they have more electrons in the outer shell and it will get bigger than its parent atom

Question 5

What is “Primary bond” based on?

Answer 5

based on electron sharing between two atoms - covalent bonding.

• ΔEN <0.4 – non-polar covalent bond
• 0.4 < ΔEN <1.8 – polar covalent bond
• ΔEN > 1.8 – ionic bond

Question 6

What does the “Covalent bond” consist of?

Answer 6

1. Single bond (sigma bond) = a covalent bond when 2 electrons – one pair of electrons – are shared between 2 atoms􏰀weaker than double bonds, but low level of reactivity (H-Cl)
2. Double bond (sigma + pi bond) = when 2 atoms share two pair of electrons (4 electrons) with each other. Strong bond (O=C=O)
3. Triple bond (sigma + 2 pi bond) = 3 pairs of electrons (6 electrons) are shared between two atoms in a molecule.

Question 7

What is the “Molecular solid”?

Answer 7

secondary bond held together by intermolecular forces

Question 8

What is the “dipole moment”?

Answer 8

Overall dipole moment is a vectoral sum of all bond dipoles in the
molecule

Question 9

When does “dipole moments” occur?

Answer 9

Occurs when there is a separation of charge. (They can occur between two
ions in an ionic bond or between atoms in a covalent bond.)

Question 10

What is a “Non-polar covalent bond”?

Answer 10

1. When atoms share electron equally = two atoms have similar or the same EA

Question 11

What is a “Metallic bond”?

Answer 11

Type of bond that occurs between atom of metals, in which the valence
electrons are free to move through the lattice (sea of electrons)

Question 12

What are “Intermolecular forces”?

Answer 12

secondary bond between molecules. (They are much weaker
than the intramolecular forces of attraction but they are important because they determine the physical properties of molecules like their BP, MP, density and enthalpies of fusion and vaporization)

Question 13

What are “London (dispersion) forces”?

Answer 13

1. Van der Waal forces
2. All molecules and atoms - it is present in even nonpolar covalent bonds molecules
3. Weakest force
4. The more electrons -> the stronger the LD forces

Question 14

What is the “Dipole-dipole moment”?

Answer 14

1. Polar molecules
2. Part of Van der Waals forces
3. Occur when the partially positively charged part of a molecule interacts with the partially negatively charged part of the neighboring molecule
4. Polar covalent bonds form dipole-dipole with neighboring molecules
5. Strongest intermolecular force

Question 15

What are “Van der Waals forces”?

Answer 15

1. General term used to define the attraction of intermolecular forces
   between molecules
2. London force and dipole-dipole moment together

Question 16

What are “Hydrogen bonds”?

Answer 16

1. Type of dipole-dipole interaction that occurs specifically between H atom
   bonded to F, O, N
2. Relatively strong force of attraction between molecules􏰀considerable
   energy is required to break those bonds
3. High BP and MP