Answer:

Explanation:
The<em> energy of a photon</em>, E, can be calculated with the Planck-Einstein equation:

Where:
- h is Planck's constant 6.626×10⁻³⁴ J.s, and
- f is the frequency of the photon or electromagnetic radiation.
Substituting with your data:

Now multiply by Avogadro's number to obtain the energy of one mole of photons:

Answer:
In percentage, the sample of C-4 remains = 0.7015 %
Explanation:
The Half life Carbon 14 = 5730 year
Where, k is rate constant
So,
The rate constant, k = 0.000120968 year⁻¹
Time = 41000 years
Using integrated rate law for first order kinetics as:
Where,
is the concentration at time t
is the initial concentration
So,
<u>In percentage, the sample of C-4 remains = 0.7015 %</u>
Answer:- 
Explanations:- In reduction the electrons are accepted and so they are written on the reactant side. When an atom accepts electrons then it forms anion. Chlorine has 7 valence electrons and it needs one more electron to complete it's octet. Since, dichlorine has two Cl atoms and each Cl atom needs one more electron to complete it's octet, two electrons are accepted by dichorine to make aqueous chloride ion. For balancing the equation, there would be two chloride ions as the reactant side has two chlorine atoms.

Answer:
T = 3,3-dimethylbut-1-ene
U = 2,3-dimethylbut-2-ene
Explanation:
The chemical reactions for the two reactions and the mechanisms of reaction are shown in the two attachments to this answer.
Hope it helps!