Mississippi Science P.7.5C.5

Science7th GradePhysical Science

The Standard

P.7.5C: Students will demonstrate an understanding of the proper use of the periodic table to predict and identify elemental properties and how elements interact.

Describe concepts used to construct chemical formulas (e.g., CH4, H2O) to determine the number of atoms in a chemical formula.

2026 Mississippi College- and Career-Readiness Standards for Science · Organization of Matter and Chemical Interactions

Teacher's field guide

What Students Need to Do: Students identify the element symbols in a chemical formula. They use subscripts to count atoms of each element and treat a missing subscript as one.
What Mastery Looks Like: Given C2H6O, a student counts two carbon atoms, six hydrogen atoms, and one oxygen atom. They find nine atoms total and explain that the 6 applies only to hydrogen.
Common Misconceptions: Students may apply the 2 in H2O to both hydrogen and oxygen, or count the 2 itself as an atom. They may say oxygen has zero atoms because O has no subscript.
How to Assess It: Exit ticket: In C2H6O, how many atoms of each element are there, and how many atoms are there total? What does the missing subscript after O mean?

Lesson moves

Give pairs two bead colors and cards labeled H2O and CH4; have them build each molecule and tally atoms by element.
Ask students to write why CO and CO2 have different numbers of atoms, even though both contain carbon and oxygen.
Give groups formula cards for CO2, CH4, and NH3; have them race to match each card with its atom counts.
Put H2O and CO2 cards beside a water bottle and a fizzy drink; ask students to count the atoms in each formula.

Free download

A ready-to-print activity worksheet aligned to P.7.5C.5, with an answer key for the teacher on its own page. No account needed.

PDF, US Letter, prints cleanly in black and white.

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