Given that rh= 2.18 x 10⁻¹⁸j, 1 nm = 1 x 10⁻⁹m, h = 6.63 x 10⁻³⁴j·s, and c = 3.00 x 10⁸m/s:
calculate the wavelength, innanometers, of the light emitted by a hydrogen atom during a transition of its electron from the n = 7 to the n = 3 principal energy level.

The wavelength the light emitted by a hydrogen atom during a transition is 1006 nm.

Explanation:

By using Rydberg's Equation we cab determine the wavelength of the light:

Where,

= Energy difference

= Rydberg's Constant

= Final energy level

= Initial energy level

We have : , Z = 1

Now by using Plank's equation we can determine the wavelength of the light emitted.

E = Energy of the emitted light

h = Planck's constant =

c = speed of light =

For the given transition the energy of the light = E

The wavelength the light emitted by a hydrogen atom during a transition is 1006 nm.

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

                                  = 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g