A sample of lead is found to contain three isotopes: 23.5% of the sample has a mass of 204 amu, 24.1% has a mass of 207 amu, and the remainder has a mass of 208 amu. What
is the average atomic mass of lead?
0 206.3 amu
207.2 amu
0 82.0 amu
206.8 amu

b) nuclear ive learned that in a pedtrodic table

weight of any object is given by

w = m*g

where m is mass of the object and g is the acceleration due to gravity.

for earth the value of g is 9.8 m/s^2 so

w=117.6 n m=12 g=?

117.6=12g => g=9.8 m/s^2

which is the force of gravity on earth.