If a sample of U-238 initially contained 1.9×1018 atoms when the universe was formed 13.8 billion years ago, how many U-238 atoms will it contain today?

i think   the answer is c hope i'm right

answer:

the reaction is type of combination reaction.

explanation:

on the product side, there are 2 molecules of bonded to fe   which means one atom of fe are combined two molecules of . so, balanced chemical equation becomes :

this reaction follows the reaction type of combination reaction. a combination reaction is defined as chemical reaction in which reactants combines together to form a single product.

while cooking a piece of 1/2 pound beef steak, a cast iron pan (2.4kg in weight) was heated 260 celsius.

answer: they produce more slow than unicellular organisms.