1. 12/12 B Day
LEQ: How can we use density to tell if
an element is pure?
1. What is one element that has similar
properties to hydrogen?
2. Would you expect sodium (Na) to be
malleable?
3. Why or why not? (Explain your answer!)
4. Would you expect xenon (Xe) to be ductile?
5. Why or why not? (Explain your answer!)
2. Today’s LEQ: How can we use density
to tell if an element is pure?
By the end of today, you should be able to…
1. SOLVE to find the density of an object using
the density equation.
2. Use data on density to determine if an
element is pure
6. Draw this in your notes:
MASS = how much
matter is in an object
(how many ATOMS
are in something)
=
7.
8. Draw this in your notes:
MASS = how much
matter is in an object
(how many ATOMS
are in something)
VOLUME = how
=
much space an object
takes up (how BIG is
the object?)
10. Draw this in your notes:
MASS = how much
matter is in an object DENSITY
(how many ATOMS (how many
are in something)
VOLUME = how
= atoms
there are
in a certain
much space an object
takes up (how BIG is
space)
the object?)
14. MASS = grams (g)
VOLUME = milliliters (mL) OR
3
centimeters cubed (cm )
DENSITY = grams per milliliter
(g/mL) OR grams per centimeter
3
cubed (g/cm )
15. SOLVE: D=
M
Mass: 15 g V
Volume: 3 mL
15 g
= 5 g/mL
3 mL
23. 1. 200 g
3
4,000 cm
2. 100 g 0.8 g/mL
3. 625 mL 0.64 g/mL
4. 16,000 g 625 cm
3
3
5. 150 g 0.75 g/cm
24. LAB TIME!
Using a triple beam balance scale:
http://www.youtube.com/watch?v=jknT_OKb6yM
25. LAB TIME!
1. Write the formula for density
2. Fill in the density triangle
3. Use the scale to measure and record
the MASS of each object
4. Use your calculator to calculate the
density or the volume of each object
(don’t forget the units!)
29. Summarizer:
3
Density of pure gold: 19.3 g/cm
Density of a 14-carat gold ring:
Mass: 157 g
3
Volume: 13.8 cm
Is 14-carat gold pure gold?
Why or why not?!