A first order reaction initially contains 1. 00 × 10²⁰ molecules. If the reaction has a half-life of 20. 0 minutes, how many molecules remain unreacted after 80. 0 minutes?.

The personal identification number that students need to apply for federal student aid

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.

28. the new systematic nomenclature was so ( that many chemists preferred to ( the older trivial names that were at least shorter. at least, that is the ostensible reason. actually, tradition seems to carry more weight than ( with some scientists.