Why are zeppelin filled with hydrogen a bad idea?

Why do sodium and neon have vastly different chemical and physical properties despite having similar atomic masses?

What is the polyatamic ion of thiosulfate

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