Chemistry Reference
In-Depth Information
Atoms will bond with other atoms until they have eight valence electrons,
which gives them stability. In a
covalent bond
, two
nonmetal
atoms share
electrons to become stable. Each shared pair of electrons creates a
bond between the two elements.
Ionic bonds
occur between
metals
and
nonmetals. In an ionic bond, one element (a metal) loses electrons
and becomes positively charged. Another element (a nonmetal) gains
electrons and becomes negatively charged. The opposite charges between
elements cause an attraction that creates an ionic bond. In this activity,
you will build Lewis dot structures and demonstrate the different types of
bonding using colored candies as electrons.
Time Required
30 minutes
Materials
2
plastic cup containing about 30 M&Ms
TM
(or other small
colorful candies)
2
periodic table of elements (see page 175)
2
3 x 5 index cards (about 40)
2
science notebook
Safety Note
please review and follow the safety guidelines at the
beginning of this volume.
Procedure
1. Create Lewis dot representations for the elements in the compound
NH
3.
To do so:
a. Write the symbol N in the center of one index card.
b. In the center of three other cards, write the symbol H.
c. Look at the periodic table and compare it to Figure 2, which
shows the number of valence electrons for elements in groups
1 and 2 and 13 through 18. Determine how many valence
electrons are found in nitrogen (N). You will see that N has five
valence electrons.
