Bohr Diagrams for Atoms/Ions

Chemical Reactions
Bohr Diagrams for Atoms/Ions
2-2
From the textbook: 5.5 Elements & the Periodic Table (p.184)
Some substances like sodium chloride, potassium bromide, and calcium chloride all produce
solutions that conduct electricity (which are called _____________). Other substances such as
vegetable oil and sugar are non-conductors, or _____________, when they dissolve in water.
Why the difference? We can answer this by looking at the types of _____________ that make
up these compounds.
The periodic table helps us to explain and _____________ physical and chemical
_____________. It is generally arranged with _____________ toward the left side
of the table, and _____________ on the right side. One exception is the lightest
element, _____________. Although it is located in the top-left corner of the
periodic table, it behaves mostly as a nonmetal.
A chemical family is a group of elements in the same vertical _____________ of the periodic
table. They tend to have similar _____________ and _____________ properties. The elements
on the far-left column are called _____________ metals, and three examples are _____, _____,
and _____. The elements in group 2 are called _____________-earth metals, and three
examples are _____, _____, and _____. Elements on the far right column are called
____________________, and 3 examples are _____, _____, and _____. The elements in the
second column from the right are called _____________, and 3 examples are _____, _____, and
_____.
We can use _________ diagrams to represent the arrangement of _____________ in
various orbits. The first orbit can have a maximum of _____ electrons. The second orbit
can have no more than _____ electrons.
Draw the Bohr diagram for lithium below (you can use Figure 5 to help, but make sure
you “create pairs”, which is the best Science 10 way):
[To check your Grade 9 knowledge of ‘Bohr Diagrams’]: A Grade 9 student drew the
Bohr diagram at the right for “helium”. What’s error did he/she make?

When elements form compounds, changes occur in the _____________ of
electrons. In some compounds, electrons are _____________ from one atom to
another, so that the atoms can have the stable electron arrangement of the
closest __________________.
As you can see in Figure 5 (and your drawing above), lithium has _____ electrons
in the first orbit and _____ electron in the second orbit. If lithium (a metal) LOSES the electron
in its outer orbit, it will look like this
but it is no longer neutral; it has formed an _____________ (a charged atom in
which the number of _____________ is different from the number of
_____________). The charge of lithium is _____, because it has 1 more proton than
electron.
When calcium forms a compound, from Figure 5 you can see that it has _____ electrons in the
outer shell. If it should lose these electrons, it will form an ion with a charge of ________
because it has 2 more _____________ than _____________.
Chemistry Ha Ha! [from the cartoon above]:
Positive ions will _________________ negative ions.

Putting it Together: Atoms
1. Define the following terms:
a) electrolyte
b) alkali metal
c) halogen
d) valence shell
2. How many protons are in these elements?
a) titanium
b) iron
c) nickel
d) radon
3. How many electrons are in these
elements?
a) manganese
b) uranium
c) argon
d) sulfur?
6. Draw Bohr diagrams ( for these atoms:
a) lithium
b) neon
c) sodium
7. What did you notice about the number of
electrons in the outer (last) shell of #6a,
and #6c? What family do they both belong
to on the periodic table?
8. For question #6b, scientists say it has a
“full outer (last) shell”. From your Bohr
diagram, why does that phrase make
sense? Where would the next electron
have to go?
9. What element is this?
4. How many neutrons are in these
elements?
a) sodium
b) bromine
5. In each of these, identify the element that
has…
a) 54 protons
b) 19 protons
c) 94 protons
d) 1 electron

Putting It Together: Ions
10. From your Bohr diagrams you just finished in your notes, how would answer a Grade 9 student
who asked you: “How do ions form from atoms?”
11. What three-letter suffix do all “negative ions” end with?
12. Using your periodic table only, write the ions (with the correct charge) for:
[note: the first one is done for you]
a) magnesium ion
b) chloride ion
Ex/ Mg 2+
c) nitride (nitrogen) ion
d) oxide ion
e) barium ion
f) potassium ion
g) aluminum ion
h) phosphide ion
13. How many electrons would there be for each of these ions?
a) Pb 2+
Normal atom: _______
Charge:
_______
Total: _______
b) As 3- Normal atom: _______
Charge: _______
Total: _______
Use the same technique as a) and b) to answer these:
c) Ti 3+
d) Ra 2+
e) Se 2-
f) Mn 2+
g) Br 1-