Answer:
a. 0.18 mol
b. 1.084 x 10²³ atoms
Explanation:
Data Given:
mass of gold (Au) = 35.12 g
a. number of moles of gold (Au) = ?
b. number of atoms of gold (Au) =?
Solution:
Part a:
To find number of moles following formula will be used
no. of moles = mass in grams / molar mass . . . . . . (1)
molar mass of gold (Au) = 197 g/mol
put values in equation 1
no. of moles = 35.12 g / 197 g/mol
no. of moles = 0.18 mol
so. number of moles of Au = 0.18 mol
_________________
Part b:
To find number of atoms following formula will be used
no. of moles = no. of atoms / Avogadro's number
Rearrange the above equation
no. of atoms = no. of moles x Avogadro's number . . . . . . . (2)
Avogadro's number = 6.022 x 10²³ atoms /mol
put values in equation 1
no. of atoms = 0.18 mol x 6.022 x 10²³
no. of atoms = 1.084 x 10²³
so.
number of atoms of Au = 1.084 x 10²³ atoms
Answer:
There are 20 atoms in hydrogen.
Explanation:
Multiply Coefficient with Hydrogens subscript. In this case the coefficient is a 4 so you multiply that with Hydrogens subscript which is 5. So it would be (4)(5)=20
Naturally occurring solid material from which a metal or valuable mineral can be extracted profitably.
Answer:
d.All of the above are correct.
Explanation:
The curve of demand moves left or right continuously. Income, patterns and preferences, related products prices as well as the population size and composition are the key factors causing demand change.