Chia dung dịch X gồm các ion: NO3-, Mg2+,3 Al +,2-SO4
thành 2 phần bằng nhau:
- Cho dung dịch BaCl2 dư vào phần 1 thu được 69,9 gam kết tủa.
- Cho dung dịch NaOH dư vào phần 2 thì lượng kết tủa lớn nhất và nhỏ nhất lần lượt
là 23,3 gam và 11,6 gam. Tính số mol của các ion trong X.

The health, management and conservation of biodiversity, is a challenge facing ecosystems worldwide. the major factors that affect the health and function of the great barrier reef are climate change and pollution. which question investigates the effects of a biotic factor on the reef ecosystem?

Which of the following is a true statement? a. individuals evolve to have adaptations. b. individuals have adaptations that can change over time. c. individuals have traits that may or may not make them successful at reproduction. d. populations cant evolve, only individual organisms.

You will create a molecular clock model for an arthropod gene. follow these guidelines to make your model: . your timeline will span from 90 million years ago to the present. the common ancestor in your model is an arthropod that lived 90 million years ago. the gene that you'll track codes for a protein in the species venom . the dna sequence youll track contains 10 nitrogen bases. you can choose the order of the bases and where the mutations occur. this gene mutates at a rate of approximately 0.76 base pairs every 17.1 million years. to build your model,/ calculate the estimated time period it takes for 1 base pair to mutate. the first time period will only show the common ancestor. at the beginning of the second time period, three lineages will diverge from the common ancestor, each with a different mutation in their gene sequences. the first and third descendant species will survive for the rest of the timeline. the second descendant species was extinct 50 million years ago. calculate how long it will take for one full base pair mutation to occur. explain your reasoning by constructing a mathematical equation