In the physical properties, it is mentioned that the element has 4 valence electrons. The elements in the periodic table are arranged such that, the number of valence electrons present in the neutral atoms belonging to a particular group is equal to the group number.
Thus, the unidentified element can be best classified as a nonmetal in period 4
Ans C)
Answer:

Explanation:
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In this case, for the described chemical reaction, we find it is:

Because it says that the iron is dissolved in a strong acid which provides addition hydrogen ions to the reaction media. Thus, for the questions attached on the figure we find:
- This a REDOX reaction because we see iron is being oxidized from 2+ to 3+ and manganese reduced from +7 to +2.
- Since it is a redox reaction and the oxidized species is that undergoing an oxidation number increase, we evidence iron goes from +2 to +3, which means iron is the oxidized species.
- In this case, for the used 59.2 mL (0.0592 L) of the 0.2000 M solution of potassium permanganate, we can compute the consumed grams of iron via stoichiometry including the 5:1 mole ratio between them in the chemical reaction:

It means that the percent of iron in that sample is:

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Strong acid does not conduct electricity. Question 4} A. H30 Question 5 } B. NaOH + CH3COOH
speed = distance / time
v = d / t
If we simplify this and isolate t, then we get t = d / v
<span>Group 1A metals typically form a positively- charged cation with a +1 charge. Since group 1A metals typically only have 1 valence electron, they will often donate this electron to a Group 7A element so both atoms will have full outer shells of electrons.</span>