The amount of energy required to raise the temperature of one gram of pure water by one degree Celsius is defined as _______________________?

Whilst I agree with Jan, I am going to do you a "disservice" in the terms that she (correctly) defined.

The "word" you are looking for is calorie.

I learned that at college many years ago.

BUT it is all over the internet.

You MUST be able to research this and get an answer before you came to a Q&A site. - Otherwise, there is no hope for you.

Let me make an additional point here.

We could have given you a one word answer that is correct: calorie.

However, if you had typed your question into google, you would have had this answer come up at the top of the page:

The SI energy unit is the joule. 4.186 Joule = 1 calories. Another common energy unit is the calorie. The calorie, cal, is defined as the amount of energy (heat) needed to increase the temperature of one gram of water by 1oC. The kilocalorie, kcal, equals 1000 small calories.

By getting the one word answer, you would have missed reading about all the other things you would be better off haveing seen.