Como se determina el numero de átomos en una ecuacion química

An alloy contains 66 g of pure zinc. what is the percentage of zinc in the alloy? express your answer to two significant figures and include the appropriate units.

Read the claim. breakfast is an important meal. it jump starts the body’s process of using calories to break down food. appetite can decrease with age, but going too long without eating causes metabolism to slow down. current research shows that incorporating legumes such as lentils and chickpeas into meals boosts metabolism for twenty-four hours. who might benefit from this claim? people who have a fast metabolism stores that sell exercise equipment people who take vitamin supplements grocery stores that sell legumes

Who discovered a pattern to the elements in 1869?