Answer:
- Acetic acid (CH₃COOH) and hydronium ion (H₃O⁺)
Explanation:
Hello,
In this case, based on the acid-base theory which states that acids are known as H⁺ donors, if we consider the direct reaction:

It is clear that the acetic acid is the first H⁺ donor as it losses one H⁺ to turn into the acetate ion. Moreover, if we consider the inverse reaction:

It is also clear that the hydronium ion is the second H⁺ donor as it losses one H⁺ to turn into water.
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Answer:
Likely
(indium.)
Explanation:
Number of atoms:
.
Dividing,
, the number of atoms by the Avogadro constant,
, would give the number of moles of atoms in this sample:
.
The mass of that many atom is
. Estimate the average mass of one mole of atoms in this sample:
.
The average mass of one mole of atoms of an element (
in this example) is numerically equal to the average atomic mass of that element. Refer to a modern periodic table and look for the element with average atomic mass
. Indium,
, is the closest match.