<u>Answer:</u> The mass defect for the formation of phosphorus-31 is 0.27399
<u>Explanation:</u>
Mass defect is defined as the difference in the mass of an isotope and its mass number.
The equation used to calculate mass defect follows:
![\Delta m=[(n_p\times m_p)+(n_n\times m_n)]-M](https://tex.z-dn.net/?f=%5CDelta%20m%3D%5B%28n_p%5Ctimes%20m_p%29%2B%28n_n%5Ctimes%20m_n%29%5D-M)
where,
 = number of protons
 = number of protons
 = mass of one proton
 = mass of one proton
 = number of neutrons
 = number of neutrons
 = mass of one neutron
 = mass of one neutron
M = mass number of element
We are given: 
An isotope of phosphorus which is 
Number of protons = atomic number = 15
Number of neutrons = Mass number - atomic number = 31 - 15 = 16
Mass of proton = 1.00728 amu
Mass of neutron = 1.00866 amu
Mass number of phosphorus = 30.973765 amu
Putting values in above equation, we get:
![\Delta m=[(15\times 1.00728)+(16\times 1.00866)]-30.973765\\\\\Delta m=0.27399](https://tex.z-dn.net/?f=%5CDelta%20m%3D%5B%2815%5Ctimes%201.00728%29%2B%2816%5Ctimes%201.00866%29%5D-30.973765%5C%5C%5C%5C%5CDelta%20m%3D0.27399)
Hence, the mass defect for the formation of phosphorus-31 is 0.27399
 
        
             
        
        
        
Bioluminescence is a chemical reaction that takes place in a living organism when the organism emits light. Bioluminescence doesn't consume or produce heat, hence it can be neither endothermic nor exothermic reaction. It emits a heatless light not heat.
For bioluminescence, it could be said that it is an exoenergetic reaction because it uses energy from a chemical reaction to produce light.
        
             
        
        
        
Answer: Volume of the 1M EtOH and water should be 0.75 ml and 9.25 ml respectively to obtain the working concentration.
Explanation:
According to the dilution law,

where,
 = molarity of stock solution = 1M
 = molarity of stock solution = 1M
 = volume of stock solution = ?
 = volume of stock solution = ?
 = molarity of diluted solution = 0.075 M    (1mM=0.001M)
 = molarity of diluted solution = 0.075 M    (1mM=0.001M)
 = volume of diluted solution = 10 ml
 = volume of diluted solution = 10 ml
Putting in the values we get:


Thus 0.75 ml of 1M EtOH is taken and (10-0.75)ml = 9.25 ml of water is added to make the volume 10ml.
Therefore, volume of the 1M EtOH and water should be 0.75 ml and 9.25 ml respectively to obtain the working concentration
 
        
             
        
        
        
Answer:
2,2,4-Trimethyl-pentane
Explanation:
Structural characteristics of the compound is as follows:
- Has five methyl group
- Has one quaternary carbon
- No. double bond
- Gives four monochloro substitution products
Compound must have straight chain of 5 carbons.
Three methyl substituents are attached to 2 and 4 carbons.
Therefore, IUPAC name of the compound will be 2,2,4-Trimethyl-pentane.