Which quantity is equivalent to 50 kilocalories

I believe this problem have these following choices:

5,000 cal

0.05 cal

5 x 10^3 cal

5 x 10 ^4 cal

Now 1 kilocalorie  = 1000 calories, therefore:

50 kilocalories * (1000 calories / 1 kilocalorie) = 50,000 calories

Since there are 4 zeroes, so the scientific notation is:

5 x 10 ^4 cal         (ANSWER)

in 1783 cavendish was working with his hydrogen gas and found that when he burned it and condensed the vapor it was water. this was very significant since it disproved the greek theory of elements completely since water was not a simple substance but the product of two gases. it was lavoisier who hearing of the experiment gave cavendish's gas the name hydrogen ("water-producer") and added that hydrogen burned by combining with oxygen and that water was a hydrogen-oxygen combination.

explanation: