Element X has two natural isotopes: X-6 (6.015 amu) and X-7 (7.016 amu). Calculate the atomic mass of element X given the abundance of X-7 is 92.5%

The rock in a lead ore deposit contains 89 % pbs by mass. how many kilograms of the rock must be processed to obtain 1.5 kg of pb?

The yearly amounts of carbon emissions from cars in belgium are normally distributed with a mean of 13.9 gigagrams per year and a standard deviation of 5.8 gigagrams per year. find the probability that the amount of carbon emissions from cars in belgium for a randomly selected year are between 11.5 gigagrams and 14.0 gigagrams per year. a. 0.340 b. 0.660 c. 0.167 d. 0.397

Which of the following units is not an official si unit