In biology the term extinct is used for species which are no longer alive. so here Ava is correct because a species has died out and is not longer alive.
Endangered species are those which are on the urge of being extinct, means they are in danger so the term "endangered"
Ava can also elaborate the terms by taking examples
Dinosaurs are extinct species. They are no longer alive or not found in any part of world. So they are called as extinct.
The term can be used for animal or plant species.
7.6% KCl I had the same problem on my semester exam for summer school
The compounds will yield Positive results for the permanganate, ninhydrin, and ceric ammonium nitrate tests are
permanganate test= ethene,
ninhydrin=aspasyic acid Phenylalanine
ceric ammonium nitrate test= methanol
<h3>What is a compound?</h3>
Generally, A compound is simply defined as a substance made up of two or more different chemical elements held together by chemical bonds that are difficult to break.
In conclusion, For the permanganate test= ethene,
ninhydrin=aspasyic acid Phenylalanine
ceric ammonium nitrate test= methanol
Read more about Compound
brainly.com/question/704297
Atomic mass of Br = 79.904
<span>Now lets say y% is abundance of 79Br. </span>
<span>Then abundance of 81Br = (100 - y) </span>
<span>mass due to 79Br = 78.9183 * y/100 = 0.789183y
</span><span>mass due to 81Br = 80.9163 x (100 - y)/100 = 0.809163(100 - y) </span>
<span>Therfore</span>
<span>0.789183y+ 0.809163(100 - y) = 79.904 </span>
<span>0.789183y + 80.9163 - 0.809163y = 79.904 </span>
<span> - 0.01998y= 79.904 - 80.9163
= - 1.0123 </span>
<span>y = 1.0123/0.01998 = 50.67% </span>
<span> 79Br = 50.67% </span>
<span>now
81Br = 100 - 50.67 = 49.33%
hope this helps</span>
Answer:
N-1
Explanation:
All nitrogen positions in purine rings (N-1, N-3, N-7 and N-9) have the potential to form hydrogen bonds. Among them, only N-1 is involved in Watson-Crick base pairing hydrogen bond with a pyridimine. N-3 and N-7 are available to form further hydrogen bonds and N-9 is involved in a N-glycosyl linkage with a desoxyribose.
