Answer:
D. a program on a computer
Explanation:
There are 2 grams remain
<h3>Further explanation</h3>
Given
t1/2 = 30 years
t = 170 years
No = 100 g
Required
Remaining sample
Solution
General formulas used in decay:

Input the value :

Question 3
Explanation:
answer -A /A chemical reaction happens when substances break apart or combine to form one or more new substances. New substances form when bonds break and new bonds form. The chemical properties of the new substances are different from those of the original substances. ... Some chemical reactions produce a precipitate.
answer- B /Chemical reactions occur when chemical bonds between atoms are formed or broken. The substances that go into a chemical reaction are called the reactants, and the substances produced at the end of the reaction are known as the products
Answer:
172,5 gramos en 3 moles
Explanation:
Espero que esto ayude a marcar el MÁS CEREBRAL !!!
Nitrogen N I think would be the answer