The elements of group 7A are[tex]\boxed{{\text{most reactive non - metals}}}[/tex]. Hence the correct option is[tex]\boxed{\text{1}}[/tex].
Further explanation:
Reactivity is defined as the tendency of the element to lose or gain an electron.
The reactivity trend of elements in the periodic table:
Across a period, the energy level remains same while the number of electrons increases. This causes the increase in nuclear charge of the atom and electrons strongly held by the nuclear forces. As a result, the reactivity of elements decreases from left to right.
Down the groups, the energy level increases while the number of electrons remains same. This causes a decrease in nuclear charge of the atom and electrons loosely held by the nuclear forces. As a result, the reactivity of elements increases from top to bottom.
In the periodic table, metals present in the left side, metalloid present in the middle, and the non-metals are present on the right side.
Since the group 7A is the 17th group of the periodic table and group 17th is present at the right side of the periodic table. Therefore, elements present in group 7A are non-metals.
Also, across the period reactivity of elements increases, therefore elements present at the most right are most reactive except noble gases. 17th is present at the most right side of the periodic table and thus elements present in group 7A are most reactive.
Hence the elements of group 7A are most reactive non-metals.
Learn more:
1.Determine the ion that represented by electronic configuration [tex]\left[ {{\text{Ar}}} \right]3{d^2}[/tex]: https://brainly.com/question/7599542
2.Determine the reason that causes water molecule a bent shape: https://brainly.com/question/1979769
Answer details:
Grade: Senior School
Subject: Chemistry
Chapter: Periodic table
Keywords: Periodic table, reactivity, metal reactivity, nonmetal reactivity, halogens, group, period and 7A.
