What does an atomic number represent in an atom?

Lewis structure and molecular geometry for nh2cl

Indicate whether the specified alkyl halides will form primarily substitution products, only elimination products, both substitution and elimination products, or no products when they react with sodium methoxide. 1-bromobutane 1-bromo-2-methylpropane 2-bromobutane 2-bromo-2-methylpropane

What is the empirical formula of c6h18o3? ch3o c2h5o c2h6o c2h5o5