
If the half-life of a sample of a radioactive substance is 30 seconds, how much would be left after 60 seconds? <span>
A. one-fourth</span>
The mass number is the number of protons plus the number of neutrons. Since there are 16 neutrons, there are 14 protons. This also corresponds to the atomic number, so this atom's atomic number is 14 which is also Silicon
Hello Lilsavage717, I believe the answer you are looking for is C. or Amino Acids. They are mainly located in living things like plants or bugs.
1) is chemical Bonds
3) Conservation of mass
5) compound
hope i helped on the ones i could answer
Milk is colloid while soil and water is a heterogeneous mixture and is a suspension mixture.