The June, 2018 issue of the Journal of Chemical Education contains an article that describes a simple, yet fascinating experiment that you and your students are going to love! It involves the use of butterfly wings from the genus Morpho. I obtained some of these wings and enjoyed experimenting with them. You will too!
HS-PS1 Matter and Its Interactions
It can be difficult to engage students in reviewing for semester exams by using worksheets or practicing problems on the whiteboard. If you are looking to change up your review plans, you might consider using a lab activity that provides opportunity to revisit many of the topics that need to be covered.
I have used several different versions of the Silver Mirror or Tollen's Test lab. I am sharing the method that has proven to be the most reliable for me. The solutions should be made fresh, the directions must be followed closely and timing is very important. I like the fact that relatively small amounts of the chemicals are required, but as always you must be vigilant with safety precautions.
This is a Chemical Reactions lab that I modified to meet NGSS guidelines.
Given the amount of one reactant, students must use stoichiometry to find the ideal amount of the second reagent to use to create purple fireworks. The teacher ignites each groups' fireworks. Ideal mixture create little or no ash. Student assignment sheet with directions (and different initial amounts) plus teacher information and sample answers are included. This is an exciting and engaging activity that can be used as a stoichiometry quiz.
Students will proceed through a pre-lab engagement activity, organize element cards based on similarities & trends, discuss trends with the class and then produce a periodic table that includes the trends discussed within the lab.