30. Describe two ways that an ion
form from an atom.
By GAINING or LOSING
electrons
#32 Name each ion in problem 31. Identify each
as an anion or cation.
a. Br -1
bromide, anion
b. Na +1
sodium, cation
c. As -3
arsenide, anion
d. Ca +2
calcium, cation
e. Cu +1
copper, cation
f. H -1
hydride, anion
#34 How many electrons does each
atom have? What group is each in?
a. nitrogen; 7 electrons group 5A
b. lithium; 3 electrons group 1A
c. phosphorus; 15 electrons group 5A
d. barium; 56 electrons group 2A
e. bromine; 35 electrons group 7A
f. carbon; 6 electrons group 4A
#36 How many electrons must each atom
lose to attain a noble gas electron configuration?
a. Ca needs to lose 2 electrons
b. Al needs to lose 3 electrons
c. Li needs to lose 1 electrons
d. Ba needs to lose 2 electrons
#38 Why do nonmetals tend to form anions
when they react to form compounds?
They are looking to fill their outer valence shell with 8 electrons
http://jchemed.chem.wisc.edu/JCESoft/CCA/CCA0/Movies/NACL1.html
#40 How many electrons must be gained by each of the following atoms
to achieve a stable electron configuration?
a. N gain 3
b. S gain 2
c. Cl gain 1
d. P gain 3
#42 Identify the kinds of ions that form each
ionic compound.
a. calcium fluoride, CaF2
Ca+2
F-1
b. aluminum bromide, AlBr3
Al+3
Br -1
c. lithium oxide, Li2O
Li+1
O -2
d. aluminum sulfide, Al2S3
e. potassium nitride, K3N
Al+3
K+1
S-2
N-3
#44 Which of the following pairs of elements
will not form ionic compounds?
a. sulfur and oxygen
b. sodium and calcium
c. sodium and sulfur
d. oxygen and chlorine
#46 Most ionic substances are brittle. Why?
When hit the cations get close to the
cations and the anions to the anions
causing REPULSIVE FORCES
#48 Explain briefly why metals are good
conductors of electricity
The loose highenergy valence
electrons allow
movement of electrons
See World of Chemistry “Metals” minute 7:40 for model of “sea of electrons”
#50 Name some alloys that you have seen or used today.
See World of Chemistry “Metals” 16:50 for examples of alloys