Does this equation support the law of conservation of mass?

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

Which of the following would have less momentum than a 52 kg cheetah running at 10 m/s?

What was bohr’s contribution to the planetary model