<u>Answer:</u> The value of
for the final reaction is 
<u>Explanation:</u>
The given chemical equations follows:
<u>Equation 1:</u> 
<u>Equation 2:</u> 
The net equation follows:

As, the net reaction is the result of the addition of reverse of first equation and the reverse of second equation. So, the equilibrium constant for the net reaction will be the multiplication of inverse of first equilibrium constant and the inverse of second equilibrium constant.
The value of equilibrium constant for net reaction is:

We are given:


Putting values in above equation, we get:

Hence, the value of
for the final reaction is 
Amount of Niobium-91 initially
= 300/91 =3.2967mol
2040 years = 3 ×680 = 3 half-lives
therefore, amount left = 0.4121mol
mass of Niobium-91 remaining = 0.4121 ×91 =37.5g
Answer:
distance between them , and mass of the objects
Explanation:
the further away a object is the weaker the gyrational pull is, and imagine lifting a anvil above your head, the anvil weight push's down upon you pulling.
Answer:
The first person to go to the moon
Explanation:
Neil Armstrong was the first person !
heres more info on NASAs page!
https://www.nasa.gov/audience/forstudents/k-4/stories/first-person-on-moon.html
Answer:
Likely the reason behind carrying them in liquid for is to condense them. liquid takes up far less space than gases do and will last far longer. they can be transformed back into gases through heating them back up. To keep them solid would require frigid temperatures but liquid will transfer more easily through space.