Question

chemical bonding review worksheet

1. which part of the atom is responsible for chemical bonding?
2. what are valence electrons(be specific)?
3. where are valence electrons located (be very specific)?
4. how many valence electrons do most atoms need to have a complete outer shell and be happy?
5. which two elements only need two valence electrons to be happy?
6. why do the elements you named in #5 only need two valence electrons?
7. how many valence electrons do elements in group 1, the alkali metals, have?
8. how many valence electrons do elements in group 2, the alkaline earth metals,
9. complete the chart:

group number number of valence electrons
13
14
15
16
17
18

Explanation:

1. Electrons are responsible for chemical bonding as they can be shared, transferred, or delocalized between atoms.
2. Valence electrons are the electrons in the outermost shell of an atom that are involved in chemical bonding.
3. Valence electrons are located in the outermost electron shell (also called the valence shell) of an atom.
4. Most atoms need 8 valence electrons to have a complete outer shell (octet rule).
5. Hydrogen and Helium only need two valence electrons.
6. Hydrogen has only one electron shell (\(n = 1\)) which can hold a maximum of 2 electrons. Helium is a noble gas with a full \(n=1\) shell (2 electrons).
7. Elements in Group 1 (Alkali Metals) have 1 valence electron.
8. Elements in Group 2 (Alkaline Earth Metals) have 2 valence electrons.

9.

• Group 13: 3 valence electrons (since group number \(13-10 = 3\) for main - group elements in this range)
• Group 14: 4 valence electrons (\(14 - 10=4\))
• Group 15: 5 valence electrons (\(15 - 10 = 5\))
• Group 16: 6 valence electrons (\(16-10 = 6\))
• Group 17: 7 valence electrons (\(17 - 10=7\))
• Group 18: 8 valence electrons (except Helium which has 2, but as a general rule for the group, we consider the octet for non - He elements in the group)

Answer:

1. Electrons
2. The electrons in the outermost shell of an atom involved in bonding
3. In the outermost electron shell (valence shell)
4. 8
5. Hydrogen and Helium
6. Hydrogen has \(n = 1\) shell (max 2 electrons), Helium has a full \(n = 1\) shell (2 electrons)
7. 1
8. 2

9.

Group Number	Number of valence electrons
14	4
15	5
16	6
17	7
18	8