When a rock first formed it contained 8 milligrams of potassium-40. How much potassium-40 would remain after three half-lives a. 1 milligram
b. 2 milligrams
c. 3 milligrams
d. 4 milligrams

Which statement correctly identifies the scientific question and describes why the question is scientific? question 1 refers to the supernatural.question 2 reflects a moral or social value.question 3 refers to something that can be measured.question 4 reflects a question that can’t be observed.

Vaccines are weakened forms of disease causing microorganisms, which are given to patients to prevent disease. after the vaccine is administered, the immune system responds by creating a(n) to recognize the a.) antibody, antibiotic b.) antigen, antibody c.)antibiotic, antibody d.)antibody, antigen

Amines amides and amino acids are categories of