<u>Answer:</u>
<em>Atomic number 75 is dedicated to an element named rhenium and has been given Re as its chemical name.</em>
<u>Explanation:</u>
With a really low concentration it is one of the rarest metals that is found in Earth's crust.
Like all other elements rhenium also has certain isotopes among with 185 and 187 are the most stable ones. Hence these two are the ones that are naturally available abundance is 34% and 63% respectively.
The correct answer is D. The solute in this solution is the solid sodium nitrate (NaNO3) which is dissolved in the solvent, the water. Solute is the minor component in a solution whereas the solvent is the major component in the solution.
The rate constant of the reaction K we can get it from this formula:
K=㏑2/ t1/2 and when we have this given (missing in question):
that we have one jar is labeled t = 0 S and has 16 yellow spheres inside and the jar beside it labeled t= 10 and has 8 yellow spheres and 8 blue spheres and the yellow spheres represent the reactants A and the blue represent the products B
So when after 10 s and we were having 16 yellow spheres as reactants and becomes 8 yellow and 8 blue spheres as products so it decays to the half amount so we can consider T1/2 = 10 s
a) by substitution in K formula:
∴ K = ㏑2 / 10 = 0.069
The amount of A (the reactants) after N half lives = Ao / 2^n
b) so no.of yellow spheres after 20 s (2 half-lives) = 16/2^2 = 4
and the blue spheres = Ao - no.of yellow spheres left = 16 - 4 = 12
c) The no.of yellow spheres after 30 s (3 half-lives) = 16/2^3 = 2
and the blue spheres = 16 - 2 = 14
Answer:
The first question is option 2
and the second question in option 1
Explanation:
If you go backwards two elements, you will find Neon (Ne). If you go forwards six, you will find Argon (Ar). so the closest will be neon
