In a sample of 400 lithium atoms, it is found that 30 atoms are lithium-6 (6.015 amu) and 370 atoms are lithium-7 (7.016 amu). What is the average atomic mass?

The reaction q+r2=r2q is found to be first order in r2 and

What is the relation between concentration of reactants and the rate of chemical reaction?

Pastoral farming is best described as a. a method of raising livestock and moving herds b. an african method of agriculture c. a method of cultivating crops on poor soils d. a common method of desert farming select the best answer from the choices provided a b c d