A sample of element Z, which has two isotopes, is made up of 75% Z-12 and 25% Z-13. Calculate the average atomic mass. Round your answer to TWO PLACES after the decimal. Enter your answer as a number (no units)

Average atomic mass  = 12.25

Explanation:

Percent abundance of Z-12 = 75%

percent abundance of Z-13 = 25%

Average atomic mass = ?

Solution:

Average atomic mass  = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass)  / 100

Average atomic mass  = (75×12)+(25×13) /100

Average atomic mass =  900 + 325 / 100

Average atomic mass  = 1225 / 100

Average atomic mass  = 12.25 amu.

the ideal gas law equation is as follows

pv = nrt

where p - pressure

v - volume

n - number of moles

r - universal gas constant

t - temperature

so if the pressure, volume and temperature are already known

we are left with n and r

since r is the universal gas constant that has a known fixed value then r too is known

so we are left with 'n'

once we know temperature volume and pressure

we can find the number of moles of gas present using the ideal gas law equation

this is not my own answer, this is an answer for the same question by the user blahblahmali. i do not claim ownership of this account.

2b2t

explanation:

2b2t