Answer:
2.
Explanation:
This should be right hopefully it is!
There are two naturally occurring isotopes of gallium: mass of Ga-69 isotope is 68.9256 amu and its percentage abundance is 60.11%, let the mass of other isotope that is Ga-71 be X, the percentage abundance can be calculated as:
%Ga-71=100-60.11=39.89%
Atomic mass of an element is calculated by taking sum of atomic masses of its isotopes multiplied by their percentage abundance.
Thus, in this case:
Atomic mass= m(Ga-69)×%(Ga-69)+X×%(Ga-71)
From the periodic table, atomic mass of Ga is 69.723 amu.
Putting the values,

Thus,

Rearranging,

Therefore, mass of Ga-71 isotope is 70.9246 amu.
Answer:
Use pOH = -log₁₀ [OH-]
Explanation:
pOH can be calculated from the concentration of hydroxide ions using the formular below:
pOH = -log₁₀ [OH-]
The pOH is the negative logarithm of the hydroxide ion concentration.
1. 1/16 x 1 000 000= 62500
2. Each half life is 5750 years long
3. The end of a half life is found by dividing the beginning of the half life by 2.
4. The number 62500 is between the 7th and the 8th half lives (refer to the number of 14C atoms on my table)
5. The 7th half life is 40250 years, and the 8th half life is 46000 years.
6. Therefore, your estimate would be a number roughly in the middle of 40250 and 46000 (for example: 43000)
Hope this helps :)
The chemical structure of 2,2,3-trimethylbutane is shown as attached document. In a condensed structural formula, a branched chain is shown in bracket ().
So according to the chemical structure, the correct condensed structural formula for this molecule is CH3C(CH3)CH(CH3)2