Answer:
19.6 J
Step-by-step explanation:
Before the ball is dropped, it has a <em>potential energy
</em>
PE = mgh
PE = 0.2 × 10 × 9.8
PE = 19.6 J
Just before the ball hits the ground, the potential energy has been converted into kinetic (<em>mechanical</em>) energy.
KE = 19.6 J
boiling, salt water will separate the salt from the water through the physical change of water from a liquid to a gas, leaving you with just salt left over.
Answer:
The pH of the solution is 5.31.
Explanation:
Let "
is the dissociation of weak acid - HCN.
The dissociation reaction of HCN is as follows.

Initial C 0 0
Equilibrium c(1-
) c
c
Dissociation constant = 

In this case weak acids
is very small so, (1-
) is taken as 1.


From the given the concentration = 0.050 M
Substitute the given value.

![[H_{3}O^{+}]=c\alpha](https://tex.z-dn.net/?f=%5BH_%7B3%7DO%5E%7B%2B%7D%5D%3Dc%5Calpha)
![[H_{3}O^{+}]=0.05\times 9.8\times 10^{-4}= 4.9\times10^{-6}](https://tex.z-dn.net/?f=%5BH_%7B3%7DO%5E%7B%2B%7D%5D%3D0.05%5Ctimes%209.8%5Ctimes%2010%5E%7B-4%7D%3D%204.9%5Ctimes10%5E%7B-6%7D)
![pH= -log[H_{3}O^{+}]](https://tex.z-dn.net/?f=pH%3D%20-log%5BH_%7B3%7DO%5E%7B%2B%7D%5D)
![=-log[4.9\times10^{-6}]](https://tex.z-dn.net/?f=%3D-log%5B4.9%5Ctimes10%5E%7B-6%7D%5D)

Therefore, The pH of the solution is 5.31.
Explanation:
At each reflecting surface (benzene and glass) there will be 180 degree phase change.
Now, for constructive interference the optical path in benzene is
.
Formula to calculate thickness of a benzene thin film is as follows.
Optical path length through benzene (
) = 
Hence, substituting the given values into the above formula as follows.
Optical path length through benzene = 
d = 
=
=
(as 1 nm = 
= 204.9 m
Thus, we can conclude that minimum thickness of benzene is 204.9 m.
Answer:
Compound B is ionic. The electronegativity difference is 2.2, which can be determined by subtracting the electronegativity of Element Y from that of Element Z. Electronegativity differences greater than 1.7 indicate ionic bonds.
Hope that helps.