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)

because u need two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei to form isotopes.

so since they all have the same shape? i mean maybe because m& m and reeses are both chocolates