Answer:
i. n = 5
ii. ΔE = 7.61 ×
KJ/mole
Explanation:
1. ΔE = (1/λ) = -2.178 ×
(
-
)
(1/434 ×
) = -2.178 ×
(
)
⇒ 434 ×
= (1/-2.178 ×
)
But,
= 2
434 ×
= (1/2.178 ×
)
434 ×
× 2.178 ×
= 
⇒
= 5
Therefore, the initial energy level where transition occurred is from 5.
2. ΔE = hf
= (hc) ÷ λ
= (6.626 × 10−34 × 3.0 ×
) ÷ (434 ×
)
= (1.9878 ×
) ÷ (434 ×
)
= 4.58 ×
J
= 4.58 ×
KJ
But 1 mole = 6.02×
, then;
energy in KJ/mole = (4.58 ×
KJ) ÷ (6.02×
)
= 7.61 ×
KJ/mole
Using ideal gas equation,
P\times V=n\times R\times T
Here,
P denotes pressure
V denotes volume
n denotes number of moles of gas
R denotes gas constant
T denotes temperature
The values at STP will be:
P=100 kPa
T=293 K
R=8.314472 L kPa K⁻¹ mol⁻¹
Number of moles of gas=3.43 mole
Putting all the values in the above equation,

V=83.55 L
So the volume will be 83.55 L.
83.55 L of radon gas would be in 3.43 moles at room temperature and pressure (293 K and 100 kPa).
Hey there! The answer to your first question is SILICON, Nickle has 28 protons, silicon has 14, 14+14=28. Its the only element thats adds up. I dont know about the 2nd one myself.
Answer:
Paired = 12
Unpaired = 0
Explanation:
Magnesium is alkaline earth metal.
It is present in second group.
Its atomic number is 12 and atomic mass 24 amu.
Electronic configuration:
Mg₁₂ = 1s² 2s² 2p⁶ 3s²
It can seen from electronic configuration that all electrons are paired because s subshell have one orbital and it can accomodate two electrons. Each s subshells in magnesium have two electrons so these are filled and have paired electrons. While p subshell have three orbitals and can accomodate six electrons two by each orbital with opposite spin thus 2p is also filled and have paired electrons.
1 mole of AGNO3 weighs 170g
so 0.6322 miles will weigh 170 X 0.6322=107.474 g