How would you find out how many valence electrons are in an element?

If there are 40 mol of NBr3 and 48 mol of NaOH, what is the excess reactant?

2.088 g sample of a compound containing only carbon, hydrogen, and oxygen is burned in an excess of dioxygen, producing 4.746 g CO 2 and 1.943 g H 2O. What is the empirical formula of the compound?

Add 5 to me. then divideby 7. of you add 12 and then subtract 7, you get 10. what number am i?

How many moles are represented by 118 grams of cobalt? cobalt has an atomic mass of 58.93amu

What is biodiversity? I don't really understand ...

A beaker contains 500 ml of 2.40M KNO3 the beaker is left uncovered so that all of the water evaporates. What mass of KNO3 crystals will remain in the beaker when the beaker is dry.

What are group 6a elements likely to do when they form ions-gain electrons or lose them? what are group 6a elements likely to do when they form ions-gain electrons or lose them? lose electronsgain electrons?

The formula for chlorine dioxide

An observation that requires measurement is called quantitative observable or qualitative

Calculate the mole fraction of each gas in a mixture of 43.6 g Xe and 36.8 g Kr. show work