1. Calculate the resistivity of the given material whose resistance is 2Ω, length and area of cross section are 15 cm and 25cm² respectedly

0.033 Ω . m

Explanation:

This is a typical problem that can be solved with the resistivity formula.

ρ = R . A / l

where R is the resistance, A is the area and l, length of the object.

We have all the data in the statement but firstly, we need to convert the area and length in m² and m, respectively because units of ρ are Ω . m

15 cm . 1 m/100 cm = 0.15 m

25 cm² .  1m² / 10000 cm² = 0.0025 m²

We replace → R = 2Ω . (0.0025 m² / 0.15) ⇒ 0.033 Ω . m

A conductive object will be more or less resistant according to the resistivity, which increases with length and decreases with area. Furthermore, resistivity is also conditioned to temperature, where as T ° increases, resistivity increases too.

the seeing the electronic configuration we can say that the element is fluorine.

fluorine is the most electronegative element in the periodic table.

but by only seeing the configuration we cannot say about its reactivity because we don't know if its configuration after excitation or by addition of electrons.

but if not then, it is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. as the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine.