How do you calculate a wavelength of light emitted when
theelcetron in doubly ionized lithium makes a transiton
frome12 to e8?

Wavelength of light emitted when  the electron in doubly ionized lithium makes a transition  from E12 to E8 is  

Explanation:

Using Rydberg's Equation for hydrogen and hydrogen like atom:

Where,

= Wavelength of radiation

= Rydberg's Constant

= Higher energy level  

= Lower energy level

We have:

The wavelength of the photon emitted when the hydrogen atom undergoes a transition is

consider the reaction below.

 no rx

at 500 k, the reaction is at equilibrium with the following concentrations.

[pci5]= 0.0095 m

[pci3] = 0.020

[ci2] = 0.020 m

what is the equilibrium constant for the given reaction?

0.042

0.42

2.4

24

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.