Fellow name: Jennifer Casey Title of Lesson: Flame Test Activity ...

Fellow
name:

Jennifer
Casey
Title
of
Lesson:

Flame
Test
Activity
Grade
Level:

10 th ,
11 th ,
and
12 th
Subject(s):

Chemistry
and
Honors
Chemistry
Summary:

This lesson is centered on performing various flame tests for students in order for
students to find periodic trends within the color changes observed. In order for students to
understand why the color changes occur, the wave-like nature of light and the concept of electron
excitation are reviewed first. The review is given through both a PowerPoint presentation and a
handout for students. The handout includes pre-questions that help the teacher gauge the prior
knowledge of students and a section of fill-in-the-blank notes that the students can answer during
the presentation. Once these concepts have been thoroughly reviewed, the flame test demonstration
can take place. Following this, there is a second handout that guides students through determining
the periodic trends in color emitted. Lastly, this lesson is concluded with an at-home assignment
where students can apply their knowledge of flame testing to two real world systems (chemical
identification and astronomy).
Time
Required:

This
whole
lesson
can
be
completed
in
a
50‐minute
class
period.

The
presentation
and
first
handout
take
no
more
than
25
minutes
to
complete,
the
flame
test
(which
consists
of
testing
seven
compounds)
takes
about
10
minutes
to
complete,
and
the
second
worksheet,
which
helps
students
establish
the
periodic
trends
associated
with
flame
testing,
can
easily
be
finished
in
the
remaining
15
minutes.
Group
Size:

There
are
no
groups
required
for
this
activity.
Cost
to
implement:

The
costs
to
implement
this
lesson
are
very
low,
as
the
salts
needed
in
this
demonstration
are
salts
that
are
readily
available
in
most
school
stock
rooms.

If
a
salt
is
unavailable,
then
that
salt
does
not
need
to
be
included,
and
a
different
chloride
salt
can
be
used
in
its
place.

Also,
the
amount
of
salt
needed
is
very
little
–
the
flame
test
requires
only
about
half‐a‐gram
to
a
gram
of
salt.
Learning
Goals:
After
this
lesson,
students
should
be
able
to:

1. 

Distinguish
which
color
of
light
has
the
highest/lowest
frequency
2. 

Comment
on
light
as
a
form
of
energy
3. 

Understand
what
the
world
“excited”
means
in
relation
to
electrons
in
an
atom
4. 

Identify
a
ground
state
from
an
excited
state
electron
configuration
5. 

Recognize
that
energy
absorbed
from
atoms
can
be
in
the
form
of
heat
6. 

Recognize
that
energy
emitted
from
atoms
can
be
in
the
form
of
light
7. 

Relate
the
idea
of
light
emission
to
chemical
identification
Introduction
/
Motivation:
**It
should
first
be
noted
that
this
lesson
relies
heavily
on
the
fact
that
students
are
comfortable
with
ground
state
electron
configurations.

They
do
not
need
to
have
learned
about
excited
state
configurations,
but
the
primary
goal
of
this
lesson
is
to
take
something
less
interesting
like
electron
configurations
and
show
how
it
explains
very
interesting
phenomena.
So
in
that
regards,
this
lesson
is
less
about
teaching
a
specific
idea,
and
more
about
relating
an
already
understood
idea
to
various
applications.**
To
introduce
the
material,
I
start
out
with
a
few
simple
examples
to
get
students
interested.

I
begin
by
asking
them
if
they
know
what
table
salt
(sodium
chloride)
looks
like
and
if
they
could
point
it
out
to
me
if
they
saw
it.

They
of
course
claim
they
can,
so
I
put
up
photos
of
sodium
chloride
and
magnesium
chloride
and
have
them
vote
for
which
one
is
table
salt.

I
then
mention
the
difficulties
associated
with
determining
what
atoms
and
molecules
make
up
the
Sun.

These
two
examples
seem
to
drive
home
the
point
that
scientists
need
a
clever
way
for
determining
what
things
are
made
of.
Following
the
introduction,
I
have
students
answer
a
few
pre‐questions
about
light
(such
as
what
it
is
and
where
it
comes
from)
and
I
have
them
play
with
a
diffraction
grating
and
write
down
what
they
notice.

We
review
their
answers
aloud
so
I
can
get
a
quick
idea
of
how
much
material
they
remember
from
middle
school.

This
leads
into
the
PowerPoint
presentation,
where
I
discuss
what
light
is
and
what
the
different
colors
represent.
Once
we
review
about
light,
the
students
work
on
the
second
part
of
the
first
handout,
which
includes
writing
electron
configurations
and
filling
out
an
electron
configuration
diagram.

We
review
the
answers
aloud
again,
giving
me
a
chance
to
gauge
their
current
understanding.
This
is
followed
by
a
return
to
the
PowerPoint
presentation,
where
we
quickly
review
filling
out
electron
configuration
diagrams.

From
here,
the
idea
of
absorption
and
emission
are
covered,
and
we
discuss
how
each
element
gives
off
certain
colors
when
heated.
This
concludes
the
PowerPoint
presentation,
and
leads
directly
into
the
flame
test
demonstration.

I
begin
this
activity
by
asking
students
for
guesses
of
what
color
table
salt
(sodium
chloride)
will
emit
when
lit
on
fire
since
it
is
a
chemical
they
are
familiar
with
and
some
might
have
seen
it
before.

We
then
check
the
color.

I
continue
to
ask
students
what
color
they
expect
to
be
emitted,
even
though
it
is
unlikely
they
will
be
able
to
immediately
determine
a
trend
–
it
is
done
more
to
keep
students
thinking,
although
I
had
no
problem
keeping
the
students
engaged
by
the
vibrant
colors.

Another
thing
to
note
is
that
it
is
best
to
save
the
salts
SrCl2
(magenta),
BaCl2
(green),
and
CuCl2
(blue)
for
last,
as
these
emitted
colors
have
the
biggest
impact
with
students.

In
order
to
make
the
colors
more
vibrant
and
to

ensure
no
contamination
of
sodium
chloride,
the
flame
test
loop
should
be
continually
cleaned
with
HCl.
Now
that
the
students
have
seen
and
recorded
the
emitted
colors,
I
hand
out
the
second
worksheet,
which
helps
guide
students
through
determining
the
periodic
trends
of
color
of
light
emitted.

The
trends
are
not
very
obvious
and
there
are
many
subtleties
involved,
so
I
debrief
the
students
afterwards
by
asking
what
results
they
saw
and
discussing
why
any
breaks
in
the
trends
occurred.
Procedure:
• Teacher
presents
motivation
for
the
upcoming
activity
(part
of
PowerPoint
presentation)
• Teacher
provides
students
with
a
diffraction
grating
and
first
worksheet,
which
students
will
work
on
(Properties
of
Light:

Pre‐Questions)
for
5
minutes
or
so
• Teacher
and
students
review
answers
to
pre‐questions
• Teacher
begins
PowerPoint
presentation
on
light
and
waves
while
students
fill
out
blanks
in
notes
(Properties
of
Light:

Notes)
• Once
teacher
finishes
this
part
of
the
lesson,
students
work
on
second
part
of
the
first
worksheet
(Behavior
of
Electrons:

Pre‐Questions)
• Teacher
and
students
review
answers
to
pre‐questions
• Teacher
begins
PowerPoint
presentation
on
excitation
of
electrons
while
students
fill
out
blanks
in
notes
(Behavior
of
Electrons:

Notes)
• Teacher
performs
flame
test
demonstration,
while
students
record
colors
emitted
by
different
chemicals
on
their
worksheet
(Flame
Test:

Data
Table)
o Have
multiple
chloride
salts
available
o Add
about
0.5
to
1.0
grams
of
each
salt
into
its
own
empty
beaker
or
flask
o Add
enough
distilled
water
to
each
beaker/flask
to
make
supersaturated
salt
solutions
o Clean
flame
test
loops
with
HCl
before
and
after
use
(best
if
each
salt
sample
has
its
own
flame
test
loop)
o Dip
flame
test
loop
in
saturated
salt
solution,
and
place
flame
test
loop
in
flame
created
by
Bunsen
burner
o Repeat
with
each
salt
sample
• Teacher
hands
out
second
worksheet
and
students
complete
the
worksheet
in
class
• Teacher
and
students
review
answers
to
worksheet
and
discuss
advantages
and
disadvantages
to
flame
testing
• Teacher
assigns
the
corresponding
homework
assignment
for
students
to
complete
Materials
List
Students
will
need:
• Diffraction
gratings
Teacher
will
need:
• Safety
goggles
• Bunsen
burner
• Flame
test
loop
• Various
chloride
salts
and
distilled
water

Safety
Issues:
This
activity
does
require
an
open
flame,
so
make
sure
to
wear
the
proper
safety
equipment
(goggles).


The
students
do
not
need
safety
equipment
as
they
are
not
participating
in
the
demonstration,
but
they
should
be
a
safe
distance
away
from
the
open
flame
at
all
times.
Lesson
Closure:
Once
the
students
have
completed
the
second
handout
that
helps
them
discover
the
periodic
trends
associated
with
flame
testing,
we
discuss
their
results.

Students
will
immediately
notice
breaks
in
the
trends,
so
we
discuss
why
this
trend
is
not
clear‐cut.

If
sodium
contamination
was
prevalent
in
the
demonstration,
this
is
a
good
time
to
discuss
why
most
compounds
had
a
yellow/orange
hue
and
how
this
can
be
a
potential
problem
with
flame
testing.

From
here,
I
mention
the
various
applications
and
tell
students
they
now
have
the
“opportunity”
to
investigate
these
applications
further
by
completing
the
homework.
The
flame
test
is
not
a
new
idea,
but
the
Powerpoint
presentation,
handouts,
and
homework
are
all
original.
Attachments:
Handout
1
‐
Flame
Test
Worksheet
Handout
2
–
Flame
Test
Thought
Questions
Powerpoint
–
Flame
Test
Activity
List
CA
Science
Standards
addressed:
• Atomic
and
Molecular
Structure