A sample of crushed rock is found to have 4.81 x10^21 atoms of gold, how many moles of gold are present in this sample? a) 7.99 x 10^-3 moles
b) 1.57 x 10^-1 moles
c) 1.25 x 10^3 moles
d) 2.47 x 10^5 moles

0.8 moles

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

\begin{gathered}n = \frac{N}{L} \\\end{gathered}

n=

L

N

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

We have

\begin{gathered}n = \frac{4.81 \times {10}^{23} }{6.02 \times {10}^{23} } = \frac{4.81}{6.02} \\ = 0.799003...\end{gathered}

n=

6.02×10

23

4.81×10

23

=

6.02

4.81

=0.799003...

We have the final answer as

0.8 moles

Hope this helps you

convalent bond :

is a chemical bond formed by the sharing of electron between 2 atoms.

it is the direct chemical bond between 2 atoms.

in bond formation atoms are involved here.

electrovalent bond:

is a chemical bond defined as electroststic attraction between 2 atoms.

it is the electrostatic attraction between 2 atoms.

in bond formation, ions are involved here.

hope it

and ur welcm

: )

chemical digestion occurs in the stomach were hcl and pepsin forms chyme, the mouth in which salivary amylase breaks down starch to form bolus, and the small intestine specifically the duodenum.