Answer:
a medicine or other substance which has a physiological effect when ingested or otherwise introduced into the body.
Explanation:

The 2 in front of
in
is <u>Coefficient.</u>
_____________________________
The
after
in the same equation is <u>sub </u><u>script</u><u>.</u>
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There are two atoms of
in 
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The water cycle is one interaction between the geosphere and the cryosphere.
Given:
Diprotic weak acid H2A:
Ka1 = 3.2 x 10^-6
Ka2 = 6.1 x 10^-9.
Concentration = 0.0650 m
Balanced chemical equation:
H2A ===> 2H+ + A2-
0.0650 0 0
-x 2x x
------------------------------
0.065 - x 2x x
ka1 = 3.2 x 10^-6 = [2x]^2 * [x] / (0.065 - x)
solve for x and determine the concentration at equilibrium.