Which of the following electron configurations is most likely to result in an element that is relatively inactive?

a. a filled energy sublevel

b. a half-filled energy sublevel

c. one empty and one filled energy sublevel

d. a filled highest occupied principal energy level

D.) Filled highest occupied principal energy level

Option (D) is the correct answer.

Explanation:

The distribution of electrons of an element in their atomic orbitals is known as electronic configuration.

For example, atomic number of neon is 10 and its electronic configuration is .

According to Aufbau's principle, in ground state atomic orbital of an atom starts to fill from the lowest energy level.

So, when highest energy level of an atom is completely filled then it becomes unreactive in nature as then it neither needs to gain or lose electrons.

Hence, we can conclude that a filled highest occupied principal energy level electron configurations is most likely to result in an element that is relatively inactive.

when 25.0 ml of 0.700 mol/l naoh was mixed in a calorimeter with 25.0 ml of 0.700 mol/l hcl, both initially at 20.0 °c, the temperature increased to 22.1 °c. the heat capacity of the calorimeter is 279 j/°c.

the equation for the reaction is:

naoh + hcl → nacl + h₂o

moles of hcl = 0.0250 l hcl ×

0.700

mol hcl

1 l hcl = 0.0175 mol hcl

volume of solution = (25.0 + 25.0) ml = 50.0 ml

mass of solution = 50.0 ml soln ×

1.00

ml soln

= 50.0 g soln

δt=t2-t1

= (22.1 – 20.0) °c = 2.1 °c

the heats involved are

heat from neutralization + heat to warm solution + heat to warm calorimeter = 0

q1+q2+q3=0

nδh+mcδt+cδt=0

0.0175 mol ×

δh

+ 50.0 g × 4.184 j·g⁻¹°c⁻¹ × 2.1 °c + 279 j°c⁻¹ × 2.1 °c = 0

0.0175 mol ×

δh

+ 439.32 j + 585.9 j = 0

0.0175 mol ×

δh

= -1025.22 j

δh=1025.22j0.0175 mol= -58 600 j/mol = -58.6 kj/mol