Check-in
• Write the electron configuration for
potassium, K.
1s22s22p63s23p64s1
• What would have to happen to a
potassium atom for it to have a noble gas
configuration? Explain.
It would need to lose 1 electron (then it would
be like Argon)
Check-in
a) What is the charge on the Sn atom after
4 electrons have been removed?
+4
b) Does Sn have a noble gas electron
configuration once the 4 electrons have
been removed?
It doesn’t have the same # of electrons as a
noble gas, but it still has 18 valence electrons!
HOMEWORK
1. Which noble gas is closest to calcium, Ca,
on the PT? What must happen to a calcium
atom in order for it to have a noble gas
electron configuration?
Argon, it must lose 2
electrons.
HOMEWORK
2. When chlorine gains an electron to
become a chloride ion with a -1 charge, it
ends up with the noble gas electron
configuration of argon. Why doesn’t it
become an argon atom?
It still has 17 protons & the # of protons
determines the type of element.
HOMEWORK
3. Explain why the elements on the right
hand side of the periodic table receive
electrons instead of giving them up.
It is easier for these elements to gain
electrons because they are closer to the
noble gases on the right side of the PT.
Card Activity!
QUESTIONS TO ANSWER
1. List 3 patterns you notice
2. What happens to the charge on an atom
when you remove electrons? Explain,
mentioning protons.
3. What happens to the charge when you add
electrons? Explain, mentioning protons.
Investigation 2.2.2 Activity!
1.Complete the table on
page 19.
2.Answer Questions 1 & 2.
3.Answer questions a-j on
page 21!
Check your work!
Element 1
(metal)
Na
Mg
Mg
Be
Mg
Ca
# of
valence
electron
s
1
2
2
2
2
2
# of Electrons lost/ ion
symbol
1 / Na+
2 / Mg2+
2 / Mg2+
2 / Be2+
2 / Mg2+
2 / Ca2+
Element
2
(nonmet
al)
F
O
Cl
F
O
Cl
# of
valen
ce
electr
ons
7
6
7
7
6
7
# of electrons
gained/ ion
charge
1 / F-
2 / O21 / Cl1 / F-
2 / S21 / Cl-
Neutral
compound
NaF
Sodium
fluoride
MgO
Magnesium
oxide
MgCl2
Magnesium
chloride
BeF2
Beryllium
fluoride
MgS
Magnesium
sulfide
CaCl2
Calcium
chloride
Check your work!
Na
1
1 / Na+
Br
7
1 / Br-
NaBr
K
1
1 / K+
Se
6
2 / Se2-
K2Se
Al
3
3 / Al3+
N
5
3 / N3-
AlN
Al
3
3 / Al3+
O
6
2 / O2-
Al2O3
Aluminum
oxide
Al
3
3 / Al3+
F
7
1 / F-
AlF3
CHECK-IN:
Which elements will combine with Sr, strontium, in a
one-to-one ratio?
Strontium loses 2 electrons and
forms a +2 charge so any of the
Group 6A elements (which gain 2
electrons to form a -2 charge)
will combine with Strontium 1:1
Would you expect the following pairs of atoms to
combine chemically to give an ionic compound? If yes,
write the formula for the compound.
a. Li & S Li+, S2b. O & S
O2-, S2-
c. Al & O Al3+, O2d. F & Cl F-, Cl-
Li2S
N/A
Al2O3
N/A
Would you expect the following pairs of atoms to
combine chemically to give an ionic compound? If yes,
write the formula for the compound.
e. I & K
I-, K+
f. H & N
H1-, N3-
g. Mg & F
Mg2+, F-
h. Mg & Na Mg2+, Na+
KI
N/A
MgF2
N/A
Would you expect the following pairs of atoms to
combine chemically to give an ionic compound? If yes,
write the formula for the compound.
i.
N & Al
N3-, Al3+
j.
Ca & Br
Ca2+, Br-
AlN
CaBr2