B. (twenty characters blah blah blah) Have a great day/night!
Answer:
No
Explanation:
The Earth would not have seasons if there is no revolution because the temperatures would not change.
<u>Answer:</u> The balanced half reaction is written below.
<u>Explanation:</u>
Reduction reaction is defined as the chemical reaction in which an atom gains electrons. The oxidation number of the atom gets reduced during this reaction.

When oxygen gas is reduced to oxide ions, the number of electron transferred are 2
The chemical equation for the reduction of oxygen gas to oxide ions follows:

Hence, the balanced half reaction is written above.
<u>Answer:</u> The atomic weight of the second isotope is 64.81 amu.
<u>Explanation:</u>
Average atomic mass of an element is defined as the sum of atomic masses of each isotope each multiplied by their natural fractional abundance
Formula used to calculate average atomic mass follows:
.....(1)
We are given:
Let the mass of isotope 2 be 'x'
Mass of isotope 1 = 62.9 amu
Percentage abundance of isotope 1 = 69.1 %
Fractional abundance of isotope 1 = 0.691
Mass of isotope 2 = 'x'
Percentage abundance of isotope 2 = 30.9%
Fractional abundance of isotope 2 = 0.309
Average atomic mass of copper = 63.5 amu
Putting values in equation 1, we get:
![\text{Average atomic mass of copper}=[(62.9\times 0.691)+(x\times 0.309)]](https://tex.z-dn.net/?f=%5Ctext%7BAverage%20atomic%20mass%20of%20copper%7D%3D%5B%2862.9%5Ctimes%200.691%29%2B%28x%5Ctimes%200.309%29%5D)

Hence, the atomic weight of second isotope will be 64.81 amu.