Answer:
Explanation:
Fe⁺²(aq) + ClO₂(aq) → Fe⁺³(aq) + ClO₂⁻(aq)
Here oxidation number of Fe is increased from +2 to +3 , so Fe is oxidised .
The oxidation number of Cl is reduced from + 4 to +3 so Cl is reduced .
So ClO₂(aq) is oxidising agent and Fe⁺²(aq) is reducing agent .

<u>Difference </u><u>between </u><u>Atomic </u><u>mass</u><u>, </u><u>relative </u><u>atomic </u><u>mass </u><u>and </u><u>average </u><u>atomic </u><u>mass</u><u> </u><u>:</u><u>-</u>
<h3><u>Atomic </u><u>Mass </u><u>:</u><u>-</u></h3>
- Atomic mass is the mass of neutrons and protons present in the nucleus of an atom .
- It is always calculated for a single element and having direct value
- For isotopes also, the atomic mass is calculated separately . Example :- <u>Carbon </u><u>1</u><u>2</u><u> </u><u>,</u><u> </u><u>carbon </u><u>1</u><u>3</u><u> </u><u>and </u><u>carbon </u><u>1</u><u>4</u><u> </u><u>have </u><u>different </u><u>atomic </u><u>mass</u><u>. </u>
- The SI unit of Atomic mass is " u" and "amu"
<h3>
<u>Relative </u><u>Atomic </u><u>mass </u><u>:</u><u>-</u></h3>
- Relative atomic mass is mean mass of the atoms of an element which is compared to the 1/12th mass of carbon - 12 .
- Carbon - 12 is taken as a relative when we calculate the relative atomic mass of any element
- For calculating relative atomic mass, we need to know the masses, percentage and abundance of all types of elements
- Relative atomic mass is a dimension less quantity
<h3><u>Average </u><u>Atomic </u><u>Mass </u><u>:</u><u>-</u></h3>
- Average atomic mass is the average mass of an atoms of a particular element by considering it's isotopes
- While we calculate average atomic mass is a standardized number. Whereas, Average atomic mass sometimes varies geologically .
- It also includes percentage, abundance and masses of given element .
- In average atomic mass, We do not compare mean value with the 1/12 mass of carbon - 12
- The unit of Average atomic mass is "Amu" or " u " .
<span>If you give it a good search, the most used answer would probably be as follows,
</span><span>In 1914 Henry Moseley found a relationship between an element's X-ray wavelength and its atomic number (Z), and therefore rearranged the table by nuclear charge / atomic number rather than atomic weight. Before this discovery, atomic numbers were just sequential numbers based on an element's atomic weight. Moseley's discovery showed that atomic numbers had an experimentally measurable basis.
</span>
Hope this helps!
Answer: C (The first species to populate an uninhabited area)
Explanation:
Blue, white, yellow, orange, red