How to find atomic mass of an element

What is a possible quantum number set for an electron in the 3s orbital of a magnesium atom

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

Describe the properties of sodium, chlorine, and sodium chloride