The answer is B, this is a synthesis reaction. A good way to identify a synthesis reaction is when there are multiple reactants, but only one product.
Answer : The volume of pure diamond is 
Explanation : Given,
Density of pure carbon in diamond = 
Moles of pure diamond = 23.7 moles
Molar mass of carbon = 12 g/mol
First we have to calculate the mass of carbon or pure diamond.
Molar mass of carbon = 12 g/mol

Now we have to calculate the volume of carbon or pure diamond.
Formula used:

Now putting all the given values in this formula, we get:

Volume = 
As we know that:

So,
Volume = 
Volume = 
Therefore, the volume of pure diamond is 
Answer 1) Option D : Discrete
Explanation : As in the example the scientist studies about the effects of growing human populations on the biodiversity which is found in a region, and where each region was selected had a different population density of humans from 1 to 10 million per 10 square miles. Then in each region the number of different species that can be found was recorded. So here the numerical data was collected for different regions. So, we can conclude it as discrete because when the variable takes on a countable number of values it is called as discrete.
Answer 2) Option D : The entertainment industry
Explanation : When people had enough time and money with them there was no need of creating the communications industry as it was a need not a luxurious thing. With the creation of Internet industry it is somewhat irrelevant. They had enough of time and money so building a labor industry seems to be a lame choice. So, the option of entertainment industry suits the best.
Part 1 :- Super gaint star have mass from 10 to 70 solar masses and brightness from 30,000 upto hundreds of thousand times the solar luminosity
blue super giant surface temperature is 20,000 to 50,000 degree Celsius example :0 Rigel its mass is around 20 times the sun mass it give light which 60,000 sun together give .
part 2 :- HR diagram : hertzsprung -Russel diagram ( attached below)
Answer:
They reduce the bond angle to be slightly lower than the tetrahedral bond angle, approximately 104.45 degrees.
Explanation:
The unshared pair of electrons or lone pair electrons in order to have the minimum repulsion possible with each other pushes the other bonding pairs closer together making the bond angle smaller or bent.
The bond angle is slightly lower than the tetrahedral bond angle of 108 degrees, leaving the water molecule with a bent molecular geometry.