Answer:
<h3>The answer is 19.3 g/cm³</h3>
Explanation:
The density of a substance can be found by using the formula

From the question
mass = 57.9 g
volume = 3 cm³
We have

We have the final answer as
<h3>19.3 g/cm³</h3>
Hope this helps you
Answer: Hsub=Hfus+Hvap
Explanation:
The molar heat of vaporization measured in kilojoules per mole, or kJ/mol is the energy needed to make vapor one mole of a liquid. .
The molar heat of sublimation measured in kilojoules per mole, or kJ/mol is the energy needed to sublime one mole of a solid,
the molar heat of fusion measured in kilojoules per mole, or kJ/mol is the energy needed to melt one mole of a solid.
Hess law helps to explain the relationship in physical chemistry stating that the total enthalpy change during the complete course of a reaction is the same whether the reaction is made in one step or in several steps.
In this context Hess’s law helps to see the several steps involved as the heat of sublimation energy is equal to the sum of vaporization energy and fusion energy.
4)
a) Natural selection will work negatively against rabbits that only eat berries as the drought is preventing berries from growing. It wont have any negative impact on rabbits that only eat grass as the grass is still surviving.
b) The statement ‘population has variations’ is backed up by the fact that the rabbits eat different things. They aren’t all the same. The statement ‘some variations are favorable’ is backed up by the fact that the rabbits that only eat grass are able to survive the drought. Their variation in eating grass instead of berries let’s them live. The statement ‘a population will change over time’ is backed up by the fact that the rabbits that only eat berries will die out. This will not only change the size of the population but going forward will create a population that has more rabbits that eat only grass on account of natural selection.
Answer:
6.63*10-7 m
Explanation:
The energy of one mole of the compound is obtained by dividing by the Avogadro number. Then the wavelength is obtained from
E= hc/wavelength as shown in the question.