Determining the Atomic Mass of Elements in a Compound Using Matrices

Introduction:

This activity is designed to show students a practical application for matrices within the context of chemistry.

Learning Outcomes:

• Students will be able to set up a system of equations to solve for the mass of an unknown element in a compound.
• Students will be able to use a matrix to solve the system.
• Students will be able to determine the atomic mass of the unknown element.
• Students will be able to identify the unknown element from the atomic mass and the periodic table.

Curriculum Alignment:

Chemistry SCOS:

• 3.02 Apply the mole concept. (Calculate the formula mass of a compound.)

Algebra 2 SCOS:

• 1.04 Operate with matrices to model and solve problems.

Classroom time required:

• 90 min

Materials needed:

• Student handouts
• Graphing calculator

Pre-activities:

• Students will need to solve system of equations using a matrix.
• Students will need to know how to determine the mass of a compound given the chemical formula.

Activities:

Students will use a matrix to determine the identity of an unknown element by finding its atomic mass.

Critical vocabulary:

• Matrix
• System of equations
• Formula mass
• Atomic mass
• Chemical formula

Comments:

This activity worked best when the chemistry teacher had the students complete the activity after they learned how to determine the mass of a compound given the chemical formula and the Algebra 2 teacher had taught them how to write systems of equations and solve them using matrices.