*The following investigations can be modified to focus on developing specific skills relevant to your class. These practicals are advantageous because they are relatively safe and inexpensive to perform, giving students the freedom to change methods and work as real scientists. For ideas on how to teach specific skills, such as reliability and validity, please click here. *

#### Science investigations for students aged 11 to 14

KS3 practical investigation that looks at how temperature affects the rate of dissolving. Students measure how long it takes for sugar cubes to dissolve in water at different temperatures. This relatively safe and inexpensive practical can be modified to teach a variety of investigative skills, such as validity and reliability. (PDF)

GCSE/KS3 practical to investigate how the rate of diffusion is affected by temperature. Students measure the rate of diffusion of food dye in water at different temperatures. At the end of the practical, students apply their understanding of diffusion and temperature to gas exchange in cold-water worms. (PDF)

#### Science investigations for students aged 14 to 16

GCSE investigation to determine how much energy is in food. This practical activity helps students determine whether Quavers or rice cakes contain more energy. Students calculate the temperature changes per gram of food to decide whether they would take rice cakes or Quavers on their mountain adventure. (PDF)

GCSE practical investigation to calculate an enthalpy change for an ice pack. Students imagine they work for a sports company that makes cool packs to treat injuries. They evaluate a reaction and determine its suitability for use in a cool pack. This method requires students to read a thermometer to the dearest 0.5 of a degree. (PDF)

#### STEM challenges

A range of different STEM challenges that can be both incorporated into lessons or clubs available at http://practicalaction.org/stem