If the abundance of the first isotope is x, the abundance of the second isotope is 1-x.
Substituting into the atomic mass formula,
This means the abundance of Bromine-79 is 54.6%, and the abundance of Bromine-81 is 45.4%.
Answer:
34.7mL
Explanation:
First we have to convert our grams of Zinc to moles of zinc so we can relate that number to our chemical equation.
So: 6.25g Zn x (1 mol / 65.39 g) = 0.0956 mol Zn
All that was done above was multiplying the grams of zinc by the reciprocal of zincs molar mass so our units would cancel and leave us with moles of zinc.
So now we need to go to HCl!
To do that we multiply by the molar coefficients in the chemical equation:
This leaves us with 2(0.0956) = 0.1912 mol HCl
Now we use the relationship M= moles / volume , to calculate our volume
Rearranging we get that V = moles / M
Now we plug in: V = 0.1912 mol HCl / 5.50 M HCl
V= 0.0347 L
To change this to milliliters we multiply by 1000 so:
34.7 mL
When we have Avogadro's number with four significant figures 6.022 x 10^23
and we have also this number 2.055 is also with four significant figures so,
the number of atoms = Avogadro's number / 2.055
= 6.022 x 10^23 / 2.055
= 2.930 x 10^23
and we can see that the result is number with four significant figures
Answer:
Option D is correct
Explanation:
The individual mass of reactants in the reaction are
Calcium Oxide (CaO) = amu
Carbon dioxide (CO2) amu
Since this reaction is a simple addition reaction in which no mass of the reactants is wasted. Also, no energy is released accompanied by conversion of mass into energy.
Hence, total mass of reactants would be equal to the mass of the product.
Thus, mass of calcium carbonate i.e CaCO3 is
amu
Hence, option D is correct
You answer is D
Mountain and Valley Breezes - Geography for Kids - KidsGeo
KidsGeo › geography-for-kids › mountai...
In the evening, the mountain slopes cool the surrounding air more quickly than the air found lower in the atmosphere. This creates a high pressure as air becomes more densely packed. The resulting high pressure causes winds to blow down the mountain towards the valley floor.