One fourth means (one half) of (one half) .
So the 18 months must be two half-lifes.
The half-life of this particular isotope is 9 months.
Answer:
mitosis
Explanation:
because mitosis is a continuous cell division process which occur in the somatic cell
Plants use sunlight during photosynthesis in order to use it to make sugar
Nucleotide!
When attached in a polymer, they become a nucleic acid.