Answer:
glucose and oxygen are the reactants of photosynthesis
Explanation:
hope it helps you
Fluorine-18 is a radioactive isotope of the element fluorine. According to Wikipedia, its half-life is 109.771 minutes, which means the amount present is halved every 109.771 minutes.
You can use the formula for half-life, such that
. You begin with 135 mg fluorine-18. We don't even need to plug in to the formula to see that after 110 min, the amount has halved to equal
67.5 mg.
What chemistry question....?
From the molarity and volume of HClO4, we can determine how many moles of H+ we initially have:
0.18 M HClO4 * 0.100 L HClO4 = 0.018 moles H+
We can determine how many moles of OH- we have from the molarity and volume of LiOH:
0.27 M LiOH * 0.030 L LiOH = 0.0081 moles OH-
When the HClO4 and LiOH neutralize each other, the remaining will be
0.018 moles H+ - 0.0081 moles OH- = 0.0099 moles of excess H+
This means that the molarity [H+] will be
[H+] = 0.0099 moles H+ / (0.100 L + 0.030 L) = 0.07615 M
The pH of the solution will therefore be
pH = -log [H+] = -log 0.07615 = 1.12
1-. Because Group 7A elements have 7 electrons in their valence shell, they need 1 more electron to complete the octet. Thus, it is generally true that all Group 7 electrons have an oxidation number of 1-. This also explains why electron affinity is largely the highest for Group 7A and lowest for Group 1A.