Answer:
in 1983, Lake Mead had a recorded water level of 1,225 feet above sea level. The closest it's been to that level in modern times was in 2000. Explanation:
First. moles is just a label for a number of things. just like a
dozen = 12, a gross = 144, a mole = 6022 with another 20 zeros after the
2
next
moles = mass / molecular weight.
molecular weight = sum of atomic mass from the periodic table
atomic mass MnO2 = atomic mass Mn + 2 x atomic mass O
= 54.94 + 2 x 16 = 86.94 g/mole
so moles MnO2 = 98.0 grams / (86.94 g/mole) = 1.13 moles
notice that I only gave 3 digits? that because of sig figs read the link below if you don't understand....
mw C5H12 = 5 x 12 + 12 x 1 = 72 g/mole
so moles C5H12 = 12.0 g / 72.0 g/mole = 0.167 moles
mw XeF6 = 131.3+ 6 x 19.00 = 245.3
so moles XeF6 = 100 g / 245.3 g/mole = 0.4077 moles
I've also provided a link to a periodic table. if you need atomic weights click on any element and it will give you the
details.
Answer:
Gravitational force between two objects depends on: a. The weight of the objects c. The mass of each object b. The distance between the objects d. Both b and c Please select the best answer from the choices provided A B C D
✓d
Answer : The average atomic mass of chlorine is, 32.37 amu
Explanation :
Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.
Formula used to calculate average atomic mass follows:
As we are given that,
Mass of isotope 1 = 34.97 amu
Percentage abundance of isotope 1 = 75.77 %
Fractional abundance of isotope 1 = 0.7577
Mass of isotope 2 = 36.97 amu
Percentage abundance of isotope 2 = 24.23 %
Fractional abundance of isotope 2 = 0.2423
Now put all the given values in above formula, we get:
![\text{Average atomic mass of element}=\sum[(34.97\times 0.7577)+(24.23\times 0.2423)]](https://tex.z-dn.net/?f=%5Ctext%7BAverage%20atomic%20mass%20of%20element%7D%3D%5Csum%5B%2834.97%5Ctimes%200.7577%29%2B%2824.23%5Ctimes%200.2423%29%5D)
Therefore, the average atomic mass of chlorine is, 32.37 amu
