i just need an explanation :) so the problem was " what is the mass of 5 molecules of water(H2O) , in grams?" my teacher said the answer is 1.50 x 10^-22 but i dont understand why. why is it not 1.50 x 10^24, why is the exponent negative?

Explanation:

The exponent is negative because water molecules are absolutely tiny. You can't see a molecule of water on the palm of your hand with your naked eyes, right? If a the mass of a molecule was 1.50 x 10^24, it'd be HUGE... like absolutely massive (possible the size of your city). Molecules are just tiny, tiny particles

answer: any goods being imported from another country may be subject to issued by the federal government are tariffs

explanation:  

tariffs are a tax on anything that are imported from abroad. government use them to protect and boost their local industries and the thought is that they encourage consumers to buy local instead of importing and they will hope will protect jobs and economy in the country that implements them