Particle Models of Mixtures and Reactions

Start with the particle model sheet, then use the concrete reading for physical and chemical steps. Assign the equation writing sheet before the balancing sheet.

Count atoms before and after in six particle diagrams, then tell a mixture from a chemical reaction. The directions on the page read: Read the text. For each pair, count each kind of atom and write the numbers in the table. Then write mixture or reaction on the Type line. An answer key is included.

Yes, both. We made it for 7th grade matter, and it works the same at home or at school. At home, a student can work through it alone and then go over it with you, which shows quickly what is solid and what needs another look. In class it works as independent practice, homework or a warm-up, and you can print one copy or a full set.

In a reaction, atoms join new partners, so the after box holds particles that were not there before. In a mixture, the same particles appear before and after.

A balanced equation has the same number of each kind of atom on both sides. Students change only the coefficients, then fill in a tally to prove the counts match.

One sheet follows concrete from limestone and clay through a kiln at about 1,450 degrees Celsius to the mixer. Students decide which steps are physical and which are chemical.

Yes. They turn descriptions such as iron reacting with sulfur into equations with formulas and an arrow. They then name the reactants and products.