2.10
The 0 after 1 is not significant and does not affect the value of the number; therefore, when the number will be rounded to two significant figures, it will become 2.1, so it will be the same.
The answer to this question would be: 3.125%
Half-life is the time needed for a radioactive molecule to decay half of its mass. In this case, the strontium-89 is already gone past 5 half lives. Then, the percentage of the mass left after 5 half-lives should be:
100%*(1/2^5)= 100%/32=3..125%
Answer:
c
Explanation:
protons are the atomic number which define an element
False (All compounds are molecules, but not all molecules are compounds. That is because a molecule can be made up of two atoms of the same kind, as when two oxygen atoms bind together to make an oxygen molecule. However, all compounds are made up of two or more different types of atoms.)
