What is the formula for calculating the energy of a photon? e = h – f e = e = h + f e = hf

E = hf

Explanation:

A photon is a particle which represents a 'quantum of light' or other electromagnetic radiation. These are particles that carry no mass and move at the speed of light.

The energy of a photon (E) can be given by Planck's equation where:

h = planck's constant = 6.626 *10⁻³⁴ Js

f = frequency of photon =

where λ = wavelength of photon.

Therefore,

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.

"the periodic table is arranged in order of atomic number."