T-rex lived in the Late Cretaceous period during the Mesozoic era. Dunno if this was precisely what you were looking for, but I hope it's helpful!
Answer:
C-14 from fossil had reached itshalf life
Explanation:
For radiactive isotopes (such as Carbon-14), per definition; the semi life or semi disintegration period; is defined as the time for which a certain mass isotope mass disintegrates to half of the atoms that make it up
For Carbon-14, this semi life period is 5730 years , and for the above example, as it is mentioned that we originally had 254 grams of C-14 but we currently have 127 grams (this is, exaclt half of the original mass of 254 grams), this leads us that 5730 years have passed since the original mass and the final mass (that is, one semi life period of C-14)
Answer:
<em>The correct option is C) OH</em>
Explanation:
In the field of chemistry, radicals can be described as atoms, molecules or ions which have at least one unpaired electron.
The formation of a radical occurs when a single covalent bond breaks so that each of the atoms that had been involved in the formation of the covalent bond can have an unpaired electron. Examples of radicals include OH, NH4+ etc.
Other option, like option B, is not true because a molecule of water does not have any unpaired electrons in its valence shell.
