Student Handout
3A – Chemical Formula / sTUDENT hANDOUT
3A – Chemical Formula / sTUDENT hANDOUT
3A – Chemical Formula
How can you represent the elements in a compound?
Molecular Model Set
Periodic table
Chemical formulas are used to represent pure substances. In this
investigation, different atoms are represented by different colored
balls. The sticks in the model set represent the bonds that hold
the atoms together. A structural diagram can be used to indicate
the arrangement of the atoms in a compound.
Follow regular lab safety procedures.
Part 1 − Simple molecules
Use the Molecular Model Set “Contents” card to match each
element with each color in the following table. Use your periodic
table to determine the element's symbol, atomic number, group and
period. Record all answers in the matching table on your answer
sheet.
Color Key for Molecular Model Set and Element Information
Color
Element
Element symbol
Atomic number
Group
Period
Black
Carbon
White
Hydrogen
Red
Oxygen
Blue
Nitrogen
Orange
Phosphorus
Yellow
Sulfur
Green
Chlorine
Purple
Sodium
Pick 5 atoms and connect them with bonds to form a compound. At
least 2 of the atoms must be the same color and at least two atoms
must be different colors.
Draw a diagram of your compound in Table 1 on your answer sheet
and determine its chemical formula.
Build the following stable simple molecules: H2O, CH4, NH3,
CCl4. Draw the structural formula in Table 2 on your answer
sheet.
Complete the analysis for Part 1 on your answer sheet.
Part 2 – Atom arrangement
1. Build the following models with the following numbers of
atoms. Draw the structural diagram and write the chemical formula
in Table 3 on your answer sheet. Make sure all atoms have the
appropriate numbers of bonds.
Models to build
Model
Carbon
Hydrogen
Oxygen
Nitrogen
A
3
8
0
0
B
3
8
1
0
C
2
7
0
1
Complete the analysis for Part 2 on your answer sheet.
Answer the questions on your answer sheet.
pasco / EC-63523
2pasco / EC-6352
pasco / EC-63301
