Answer:
Wt. Avg. Atomic Weight => 63.35457 amu
Explanation:
Given Isotopic %Abundance fractional Wt Avg
At. Mass (amu) abundance contribution
Cu-63 62.93 69.09 0.6909 43.4783
Cu-65 64.9278 20.0668 0.200668 20.0668
Wt Average of all isotopes = ∑Wt Avg Contributions
= 43.4783 amu + 20.0668 amu = 63.35457 amu
2. Because a cumulonimbus cloud is a towering vertical cloud
Answer: A balanced equation for the given reaction is
.
Explanation:
The reaction equation will be as follows.

Number of atoms on the reactant side is as follows.
Number of atoms on the product side is as follows.
Since number of atoms on both the reactant and product sides are equal. Hence, the reaction equation is balanced.
Thus, we can conclude that a balanced equation for the given reaction is
.
Answer:
New volume is 25.0 mL
Explanation:
Let's assume the gas sample behaves ideally.
According to combined gas law for an ideal gas-

where,
and
represent initial and final pressure respectively
and
represent initial and final volume respectively
and
represent initial and final temperature (in kelvin) respectively
Here,
,
,
and 
So, 
So, the new volume is 25.0 mL