Aradioactive isotope that can be followed through the steps of a chemical reaction is an indicator.

As shown in fig. p3.64, a closed, rigid tank fitted with a fine-wire electric resistor is filled with refrigerant 22, initially at 2108c, a quality of 80%, and a volume of 0.01 m3. a 12-volt battery provides a 5-amp current to the resistor for 5 minutes. if the final temperature of the refrigerant is 408c, determine the heat transfer, in kj, from the refrigerant.

Scientific models are based on current knowledge, which can limit their effectiveness when new discoveries are made.

The built in flash in a compact camera is usally capable of giving correct exsposure for distance up to how many meters?