Use the periodic table, find the neutral atom that has the same electron configuration as 1s2 2s2 2p6
a.)boron
b.)neon
c.)phosphorus
d.)carbon

Option B= neon

Explanation:

The given electronic configuration is of neon. Neon is noble gas with atomic number 10.  The noble gases configurations are used for abbreviated electronic configuration

For example, the atomic number of neon is ten and sodium is eleven. The abbreviated electronic configuration of sodium is written by using the neon abbreviation in following way:

The electronic configuration of neon is given below:

Ne₁₀ = 1s² 2s² 2p⁶

The abbreviated electronic configuration of sodium:

Na₁₁ = [Ne] 3s¹

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

the answer is 0.42 is that is an option. this question provides no info