He valence of selenium depends on which compound it is in. Selenium is very similar to sulfur. It may have a valence of 6; example selenium hexafluoride SeF6, selenium trioxide SeO3
<span>4; example selenium tetrafluoride SeF4, selenium dioxide SeO2 </span>
<span>2; example selenium difluoride SeF2, selenium dichloride SeCl2 </span>
<span>and -2; example hydrogen selenide H2Se</span>
<em>Thermal energy</em> is the sum of the kinetic and potential energies of all the particles in an object.
Assume that you have 250 gL of water and 1 kg of water at the same temperature.
Then, each water molecule has the same kinetic energy.
The larger sample contains four times as many molecules, so it contains four times as much thermal energy.
Thus, thermal energy is directly proportional to mass.
In symbols, <em>KE </em>∝ <em>m</em> or <em>KE = km</em>.
The graph of a direct proportion is a <em>straight line passing trough the origin</em>.
It should look something like the graph below.
Jamal is 2 miles away from his home.
Option B.
<h3><u>Explanation:</u></h3>
The initial distance of Jamal from his home is 8 miles. He needs to return home from his trip.
The speed that Jamal kept was constant for 30minutes and he drove at a speed for 12 miles per hour.
Speed of Jamal = 12 mph.
Time of travel = 30minutes =0.5 hours.
So distance traveled by Jamal = 
miles. = 6miles.
Initial distance of Jamal = 8 miles.
So final distance = 
miles = 2miles.
So Jamal is 2 miles away from his home.
The entropy of the given reactions increases (S° > 0):
- 2C2H6(g) + 7O2(g) ----> 4CO2(g) + 6H2O(g) ---> S° > 0.
- NH4Cl(s) ----> NH3(g) + HCl(g) ---> S° > 0.
<h3>What is entropy?</h3>
Entropy measure how disordered a system is. It a measure of how dispersed or random the total energy of a system is. The symbol for entropy is S.
A system in which entropy increases is one in which S° > 0.
The entropy of a system decreases when S° < 0.
Entropy of a system increases (S° > 0) if any change results in an increase in temperature, increase in number of molecules, or an increase in volume.
Considering the given systems, the entropy changes is as follows:
- 2C2H6(g) + 7O2(g) ----> 4CO2(g) + 6H2O(g) ---> S° > 0.
- 2CO2(g) + N2(g) ---->2CO(g) + 2NO(g) --> no change
- 2N2(g) + O2(g) -----> 2N2O(g) ---> decreases
- S (s,rhombic) + 2CO(g) ----> SO2(g) + 2C (s,graphite) ---> no change
- NH4Cl(s) ----> NH3(g) + HCl(g) ---> S° > 0.
In conclusion, an increase in volume and moles of substances results in entropy increase.
Learn more about entropy at: brainly.com/question/26691503
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Answer: B. Hydrolysis (adding water)
Explanation:
When peptide bonds join two or more amino acids together, this is refered to as a peptide. A polypeptide simply means several amino acids. We should also note that proteins contains polypeptides.
The reaction that is capable of breaking polypeptides into their component amino acids is hydrolysis. This simply means a chemical process whereby a water molecule is being added to a particular substance.
