In this case, we are going to assume that there are 100 atoms to make things easier.
Let R% be the abundance of n-15. With this in mind, we calculate the abundance of n-14 to be 100%-R%
14.0031*(100-R)% + 15.001 * R%= 14.00674
In this case, we can delete or ignore the % sign since we do not want to carry it around, however, we need to keep in mind that the final answer is in %
14.0031*(100-R) + 15.001 * R= 14.00674
1400.31-14.0031R+15.001R=1400.674
0.9979R=0.364
R=0.3648
Then, the abundance of n-15 is 0.3648%
I’m distilled water all of the dissolved substances mixed in water have been removed by evaporation.
I believe the correct answer would be that b<span>oiling points and melting points are similar because they both involve the change in a state of a material, but they are different because boiling point involves a change from a liquid to a gas and melting point involves a change from a solid to a liquid. Boiling and melting are phase changes that can happen to a substance however they differ in the process that happens.</span>
Here we have to compare the Bohr atomic model with electron cloud model.
In the Bohr's atomic model the electrons of an element is assumed to be particle in nature. Which was unable to explain the deBroglie' hypothesis or the uncertainty principle and has certain demerits.
The uncertainty principle reveals the wave nature of the electrons or electron clod model. The Bohr condition of a stable orbits of the electron can nicely be explained by the electron cloud model, the mathematical form of which is λ = nh/mv, where, λ = wavelength, n is the integral number, h = Planck's constant, m = mass of the electron and v = velocity of the electron.
The integral number i.e. n is similar to the mathematical form of Bohr's atomic model, which is mvr = nh/2π. (r = radius of the orbit).
Thus, the electron cloud model is an extension of the Bohr atomic model, which can explain the demerits of the Bohr model. Later it is revealed that the electron have both particle and wave nature. Which is only can explain all the features of the electrons around a nucleus of an element.
The more kinetic energy a substance has, the warmer it will be and the faster particles will be moving, which reduces the density of the substance