Answer:
number of moles = 6.393 moles
Explanation:
One mole of any substance contains Avogadro's number (6.022 * 10^23) of atoms.
Therefore, to know the number of moles that contain 3.85 * 10^24 atoms, all we have to do is cross multiplication as follows:
1 mole ......................> 6.022 * 10^23
?? moles ..................> 3.85 * 10^24
number of moles = (3.85 * 10^24 *1) / (6.022 * 10^23)
number of moles = 6.393 moles
Hope this helps :)
Answer:
option c) 3 is the correct option
Explanation
as we know that 3rd principal energy level contains 3 sub levels,which are named as s,p and d. These sub levels further contain different numbers of orbitals,
and these sub levels can be termed as regions of probability of finding an electron, and each orbital may have a maximum number of two electrons in it.
Answer: After three half-lives 1/8 (12.5%) of the original sample remains
Using the length given '12 m', because the shape of the object is a square all sides are congruent.
Basically 12+12+12+12=48 or 12 x 4= 48
The answer is 48 m
Answer: 1. The empirical formula is 
2. The molecular formula is
Explanation:
If percentage are given then we are taking total mass is 100 grams.
So, the mass of each element is equal to the percentage given.
Mass of P = 37.32 g
Mass of N = 16.88 g
Mass of F = 45.79 g
Step 1 : convert given masses into moles.
Moles of P =
Moles of N =
Moles of F =
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For P = 
For N =
For F =
The ratio of P: N: F= 1: 1: 2
Hence the empirical formula is
The empirical weight of = 1(31)+1(14)+2(19)= 82.98 g.
The molecular weight = 82.98 g/mole
Now we have to calculate the molecular formula.
The molecular formula will be=
