Compounds are atoms or molecules that are chemically bonded together to form a different molecule or compound. The process could be written as a chemical reaction. A mixture is when two elements or compounds are mixed together but do not react, ie no chemical reaction between the two occurs.
<u>Answer:</u>
The height of ramp = 124.694 m
<u>Explanation:</u>
Using second equation of motion,

From the question,
u = 31 m/s; s = 156.3 m, a=0
substituting values

t = 
= 5.042 s
Similary, for the case of landing
t = 5.042 s; initial velocity, u =0
acceleration = acceleration due to gravity, g = 9.81 
Substituting in 

h = 124.694 m
So height of ramp = 124.694 m
Hello,
The answer is option A "Venus".
Reason:
The planet Venus spins the wrong way many scientists are not sure why. Its not options B, C, or D because these planets spin the same way the as each other. (besides Venus) Therefore the answer is option A.
If you need anymore help feel free to ask me!
Hope this helps!
~Nonportrit
It takes more energy to remove the second electron from a lithium atom than it does to remove the fourth electron from a carbon atom because its inner core e, not valence e. C's 4th removed e is still a valence e. And also <span>because more nuclear charge acting on the second electron, it is more close to the nucleus, thus the the protons attract it more than the 4th electron.</span>