<span>E=hν</span> where E is the energy of a single photon, and ν is the frequency of a single photon. We recall that a photon traveling at the speed of light c and a frequency ν will have a wavelength λ given by <span>λ=<span>cν</span></span>λ will have an energy given by <span>E=<span><span>hc</span>λ</span></span><span>λ=657</span> nm. This will be <span>E=<span><span>(6.626×<span>10<span>−34</span></span>)(2.998×<span>108</span>)</span><span>(657×<span>10<span>−9</span></span>)</span></span>=3.0235×<span>10<span>−19</span></span>J</span>
So we now know the energy of one photon of wavelength 657 nm. To find out how many photons are in a laser pulse of 0.363 Joules, we simply divide the pulse energy by the photon energy or <span>N=<span><span>E<span>pulse </span></span><span>E<span>photon</span></span></span>=<span>0.363<span>3.0235×<span>10<span>−19</span></span></span></span>=1.2×<span>1018</span></span>So there would be <span>1.2×<span>1018</span></span><span> photons of wavelength 657 nm in a pulse of laser light of energy 0.363 Joules.</span>
NOOOO NO thats not true at all
<span>Esters can be shown in text as: RCOOR or (occasionally) ROCOR.</span>
Based on the bond energies given, the enthalpy change for the reaction of is -33 kJ and the reaction is exothermic.
<h3>What is the change in bond energy of a reaction?</h3>
The change in bond energy of a reaction is calculated using the formula below:
- change in bond energy = sum of energies of bonds broken - sum of energies of bonds formed
A reaction is exothermic if the change in bond energy is negative.
A reaction is endothermic if the change in bond energy is positive.
Given the bond enery values above:
sum of energies of bonds broken = 4 × C-H + Br-Br
sum of energies of bonds broken = 4 × 413 + 193 = 1845 kJ
sum of energies of bonds formed = 3 × C-H + C-Br + H-Br
sum of energies of bonds formed = 3 × 413 + 276 + 363 = 1878 kJ
Thus;
change in bond energy = 1845 - 1878 = -33 kJ
- The reaction is exothermic because the change in bond energy is negative.
Therefore, the enthalpy change for the reaction of is -33 kJ and the reaction is exothermic.
Learn more about enthalpy change at: brainly.com/question/11628413
<h2>receptors belong to the autonomic nervous system !</h2><h2> BRAINLIEST PLEASE !</h2>
