"<span>Covered with an enormous sheet of ice" would most likely match Europe, although it should be noted that this was a while ago and changes with time. </span>
Secondary succession occurs when a natural devastating calamity or event takes place such as hurricane and forest fire. It is often faster compared to primary succession because there are available resources already including soil, roots, seeds and other vegetative organs from plants can be found underground.
Answer:
When the pKa is 6.0, we can determine the fraction of protonated H is by:
pH = pKa + log [A]/[HA]
Where
A = Deprotonated imidazole side
HA = Protonated side
Given, pH = 5.0
5 = 6 + log [A]/[HA]
log [A]/[HA] = -1 (take antilog of both side)
[A]/[HA] = 0.1
The ratio of the deprotonated imidazole side chain to the protonated side chain at pH 5.0 = 0.1
Given, pH = 7.5
7.5 = 6 + log [A]/[HA]
log [A]/[HA] = 1.5 (take antilog of both sides)
[A]/[HA] = 31.62
The ratio of the deprotonated imidazole side chain to the protonated side chain at pH 5.0 = 31.62