<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>
Answer: "physical change" .
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This would be a "physical change" . ________________________________________________________
<u>Note</u>: This would change from a "solid" to a "liquid" / mere rearrangement of molecules/ NOT a new chemical substance—hence, a "physical change".
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i think it is the cell wall.
D. Magma is injected into surrounding rock forming an igneous intrusion.
Igneous intrusion forms when magma from under the surface of the earth is slowly pushed up to occupy spaces or cracks found among rocks and cools down and solidifies before it reaches the surface of the earth.
<span>Carbon (C) is most likely to form covalent bonds with Beryllium (Be) or Sodium (Na) because they are both metals and covalent bonds are metals that share their valence electrons with the gases / non-metals to get to the stable octet. Krypton is a gas and Selenium is a metalloid</span>
