<span>The oldest known vascular plants in the northern hemisphere are Devonian
This is true</span>
<h3><u>Answer;</u></h3>
A. <em>18 hydrogen atoms </em>
<h3><u>Explanation;</u></h3>
- <em><u>Alkanes are group of hydrocarbon that are saturated</u></em>. They are saturated in the sense that each carbon atom has maximum number of hydrogen atoms.
- <em><u>The homologous series of alkanes has a general formula of CₓH₂ₓ₊₂.</u></em>
- Therefore,<u><em> an alkane with 8 carbons will have; (2×8) +2 = 18 hydrogen atoms. </em></u>Thus, the formula of the hyrocarbon will be; C₈H₁₈.
Answer:
us humans need a balanced ecosystem because its what keeps us alive. when having a balanced ecosystem we have cleaned water, purified air, maintained soil, regulates our climate, recycles nutrients, and provides us with food.
The answer is; C
Fossil fuels are the remains of an organism that lived in the past and have been preserved or their impression has been preserved. Fossils are studied to identify the difference (genetic and phenotypic) between past and future related organism and are carbon dated to determine the time in which the organisms existed. The study of fossils is called paleontology.
