Understanding Celsius and Fahrenheit Scales Video Lecture | Science Class 7

Look at the two thermometers
below.
Identify which is Celsius and
which is Fahrenheit, and then
label the boiling and freezing
points of water on each.
Now, the Celsius scale
is what's used in
the most of the world.
And the easy way to tell that
you're dealing with the
Celsius scale is on the Celsius
scale, 0 degrees is
freezing of water at standard
temperature and pressure, and
100 degrees is the boiling point
of water at standard
temperature and pressure.
Now, on the Fahrenheit scale,
which is used mainly in the
United States, the freezing
point of water is 32 degrees,
and boiling of water
is 212 degrees.
As you could tell, Celsius,
the whole scale came from
using freezing as 0 of regular
water at standard temperature
and pressure and setting
100 to be boiling.
On some level, it makes a little
bit more logical sense,
but at least here in the U.S.,
we still use Fahrenheit.
Now let's figure out which of
these are Fahrenheit and which
are Celsius.
Now remember, regardless of
which thermometer you're
using, water will always
actually boil at the exact
same temperature.
So Fahrenheit, 32 degrees, this
has to be the same thing
as Celsius 0 degrees.
So let's see what happens.
So when this temperature right
here is 0, this one over here,
it looks like it's negative
something.
So this one right here doesn't
look like Celsius.
Here, if we say this is Celsius,
this looks pretty
close to 32 on this one.
Let me do that in
a darker color.
So this one right here looks
like Celsius, and this one
right here looks like
Fahrenheit.
And the way I was able to tell
is that the 0 degrees Celsius
needs to be the same thing
as 32 degrees Fahrenheit.
In both cases, this is
where water freezes,
the freezing point.
That is water freezing.
And let's make sure
we're right.
So if this is the Celsius scale,
this is where water
will boil, 100 degrees Celsius,
and that looks like
it is right about 212
on the other scale.
So right there is where water
is boiling at standard
temperature and pressure.
So this thing on the right,
right here, I guess I'll
circle it in orange,
that is Celsius.
And then the one on the left,
I'll do it in magenta, the one
on the left is Fahrenheit.