Answer: Option (D) is the correct answer.
Explanation:
Vapor pressure is defined as the pressure exerted by the vapors which are present on the surface of a liquid.
For example, vapor pressure of water at room temperature is 0.0313 atm.
On the other hand, the temperature at which the vapor pressure of a liquid equals atmospheric pressure is known as boiling point.
For example, boiling point of water at room temperature is 
.
Thus, we can conclude that vapor pressure can be described as the pressure exerted by a gas above the surface of its liquid.
Resistance of a material being scratched in known as: Hardness
Answer:
The percentage abundance of Eu isotopes are 52 % and 48 %
.
Explanation:
The formula for the calculation of the average atomic mass is:
Given that:
Since the element has only 2 isotopes, so the let the percentage of first be x and the second is 100 -x.
For first isotope,:
% = x %
Mass = 151.0 amu
For second isotope :
% = 100 - x
Mass = 153.0 amu
Given, Average Mass = 151.96 amu
Thus,
Solving for x, we get that:
x = 52 %
<u>Thus percentage abundance of Eu isotopes are 52 % and 48 %
.</u>
8.4 moles equals 469.14g Fe
