Chapter 6- Chemical bonding

Question 1

Define valence electrons

Answer 1

The electrons in the outermost energy level of the atom that will determine how an atom will react in a chemical reaction.

Question 2

Define the term ion.

Answer 2

Any charge particle.

charge is created when a neutral atom gains or loses electrons.

Question 3

Define the term electronegativity

Answer 3

A measure of the tendency of an atom to attract a bonding pair of electrons towards itself.

Question 4

How do chemical bonds between 2 atoms or molecules form?

Answer 4

They form when valence electrons are rearranged between the two atoms or molecules to hold them together.

Question 5

Why do atoms form chemical bonds?

Answer 5

Atoms form chemical bonds to reach a more stable(full) electronic structure.

Question 6

What is the difference between lewis structure and couper structure?

Answer 6

Couper structure is only used for covalent molecules and the valence electrons are indicated via lines, whilst with the lewis structure the valence electrons are indicated via dots and crosses

Question 7

What are covalent bonds?

Answer 7

A sharing of at least one pair of electrons by two non-metal atoms.

Question 8

Mention characteristics of covalent bonds.

Answer 8

• non-metal binds whit non-metal.
• forms a molecule.
• very strong bonds( outermost energy levels overlap).
• normally forms liquids(l) and gasses(g) at room temperature.
• Valence electrons are shared (electron sharing).

Question 9

What is non-polar covalent bond and polar covalent bond?

Answer 9

Non-polar covalent= shared equally( an equal sharing of electrons)
Polar covalent bond= unequally shared( unequal sharing of electrons leading to a dipole forming)

Question 10

What are ionic bonds?

Answer 10

A transfer of electrons and subsequent electrostatic attraction.

Question 11

Mention some characteristics of ionic bonds.

Answer 11

• When metals and non-metals react.
• forms a crystal structure referred to as formula unit.
• relatively strong bonds.
• normally forms solids at room temperature.
• valence electrons are lost by metals, gained by non metals(ions are formed)(electron transfer)

Question 12

What is a metallic bond?

Answer 12

Being between a positive kernel and a sea of delocalized electrons.

Question 13

Mention characteristics of metallic bonds.

Answer 13

• when metals react with each other.
• valence electrons form a sea of delocalized electrons.
• core electrons and nucleons form a positive atomic kernel which remains closely packed together.
• electrons that move around freely give metals electric conductibility.
• very strong bonds- able to reshape the metal lattice, but it won’t break.
• mostly forms solids(s) at room temperature.