My guess would be "B) they were produced by volcanoes" because hawaii has a bunch of volcanoes and volcanoes can produce extra land. While the other answers wouldn't make sense. Definitely B.
The designed world is changed regularly by inovations and new technology.
Hope I could help.
Melamine should be the right answer, i hope this helps.
The enthalpy of reaction or ∆H reaction is the difference between the bond energy of the reactants and the bond energy of the products.
<h3>What is ∆H reaction?</h3>
The term ∆H reaction refers to the heat that is evolved or absorbed in a chemical reaction. It is also known as the enthalpy of reaction.
The question is incoherent but I will try to answer as much as possible. Using the values of bond energy, ∆H reaction = Bond energy of reactants - bond energy of products. This will give us the enthalpy of reaction.
Learn more about bond energy: brainly.com/question/1657608
Explanation:
The given data is as follows.
Mass = 27.9 g/mol
As we know that according to Avogadro's number there are
atom present in 1 mole. Therefore, weight of 1 atom will be as follows.
1 atoms weight =
In a diamond cubic cell, the number of atoms are 8. So, n = 8 for diamond cubic cell.
Therefore, total weight of atoms in a unit cell will be as follows.
= 
= 
Now, we will calculate the volume of a lattice with lattice constant 'a' (cubic diamond) as follows.
= 
= 
=
Formula to calculate density of diamond cell is as follows.
Density = 
= 
= 2918.1 
or, = 0.0029 g/cc (as 1
)
Thus, we can conclude that density of given semiconductor in grams/cc is 0.0029 g/cc.