Answer:
weak bonds break and strong bonds form
Explanation:
An exothermic reaction is a chemical reaction in which heat energy is evolved during the reaction process.
Bond formation requires energy while bond breakage releases energy. More energy is needed for the formation of weak bonds as compared to strong bonds.
<em>Hence, when weak bonds break, they release more energy than needed to make a corresponding strong bond leading to the release of the remaining energy as heat.</em>
 
        
             
        
        
        
<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:
On the periodic table, each column is called a group. So, the answer is D. groups.
Explanation:
A) is incorrect because the rows on the periodic table are called periods.
B) is incorrect because the elements are what is organized on the periodic table.
C) is incorrect because the periods are the rows on the periodic table.
D) is the correct answer because the columns on the periodic table are called groups.
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There are 54 Protons in Xe and 77 Neutrons in Xe.
        
             
        
        
        
 A molecule is usually reserved to represent the smallest particle of a compound.