Basics of H-O-N-C 1-2-3-4 bonding

What is a valence electron?

• an electron that is found in the outermost shell of an atom.

• an electron found in the innermost shell of an atom.

• an electron found in the middle shell.

Answer explanation

Valence electrons are on the outermost shell, there can be between 1 and 8 valance electrons for any given element.

Which of the following has a full valence shell?

• Oxygen

• Helium

• Hydrogen

• Carbon

Answer explanation

The noble gases, the elements in group 18/8A have complete valence shells.

How many valence electrons in this structure?

• 6

• 5

• 4

• 7

Answer explanation

Each dot in the Lewis structure represents one valance electron.

Why are the atoms attached to Carbon, putting Carbon in the middle of this molecular structure

• Carbon is magnetic

• Carbon has the most mass, thus the most gravitational pull

• Carbon is diamonds

• Carbon can make up to 4 bonds, the most possible

What is the number of valence electrons for Oxygen?

• 8

• 6

• 2

• 1

Answer explanation

Oxygen is in Group 16/6A so it has 6 valance electrons on its outermost ring.

Atoms will gain/lose/share electrons to have...

• A full outer shell of electrons

• One electron short of a full shell

• 2 valence electrons

• their time in the sun

Answer explanation

This is the octet rule! If something loses electrons (a cation) to have a full valance shell it needs to react with something that gains electrons (an anion) which will then have a full valance shell. When nonmetal bond with each other they can share electrons to form covalent bonds so that all of the atoms have a full valance shell.

According to the diagram below, how many bonds will this atom need to make to be stable?

• 1

• 2

• 3

• 4

Answer explanation

Each dot in the Lewis structure represents one valance electron. This means that carbon needs 4 more to have a full octet.

How many more valence electrons does Oxygen need to be stable?

• 6

• 2

• 4

• It's already stable with 8

Answer explanation

Each dot in the Lewis structure represents one valance electron. This means that oxygen needs 2 more to have a full octet.

How many bonds can this Phosphorus atom make? (hint: how many more electrons does it need for a full shell)

• 5

• 3

• 13

• 8

Answer explanation

There are 5 electrons on the valence level so P needs 3 more to have a full octet on its valence level.

How many more electrons does Hydrogen need to have a full shell?

• 1

• 7

• 2

• 8

Answer explanation

Each dot in the Lewis structure represents one valance electron. Remember that Hydrogen is an exception to the octet rule. It only needs 2 electrons, a duet, because it is so small.