131 iodine has a half-life of 8.04 days. assuming you start with a 1.53 mg sample of 131 iodine, how many mg will remain after 13.0 days?

Tortoise shells and snail shells are similar in function: they protect the organism from predators. based on a comparison of the organisms in the images, what can you conclude? 1. tortoises and snails have homologous organs, and they’re evolutionarily related. 2. tortoises and snails have homologous organs, and they belong to same species. 3. tortoises and snails have analogous organs, and they belong to the same species. 4. tortoises and snails have analogous organs, and they don’t belong to the same species. 5. tortoises and snails have analogous organs, and they aren’t evolutionarily related.

Iknow this isn't a question, but is there someway to ask a question under public safety or is there no category for it? i don't know if i'm overlooking it or not.

Dna is a polymer of which consist of a sugar, a phosphate group, and a a. amino acids; nucleotide b. nucleic acids; nucleotide c. nucleotides; nitrogenous base d. nucleotides; nucleic acid e. proteins; nucleotide