Question

a student has 25 grams of 20 °c water inside an insulated container with a lid. the student plans to collect evidence over two trials on thermal energy transfer by adding another substance to the container and then measuring the temperature after time has passed. which two materials will yield the best evidence of thermal energy transfer within the closed system? 25 grams of 0 °c ice 50 grams of 20 °c water 25 grams of 50 °c iron (fe) 50 grams of 20 °c iron (fe)

Explanation:

Step1: Understand thermal energy transfer

Thermal energy transfers from high - temperature to low - temperature substances.

Step2: Analyze each option

• 25 grams of 0°C ice: There is a temperature difference with 20°C water, so heat will transfer from water to ice, changing ice's state and water's temperature.
• 50 grams of 20°C water: No temperature difference, so no net thermal energy transfer.
• 25 grams of 50°C iron: There is a temperature difference, heat will transfer from iron to water.
• 50 grams of 20°C iron: No temperature difference, so no net thermal energy transfer.

The best evidence of thermal energy transfer will come from substances with a temperature difference from the initial 20°C water.

Answer:

25 grams of 0°C ice, 25 grams of 50°C iron