I’m not sure quite sure about this one please help

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

Chen drew a diagram to compare the ways in which different organisms obtain nitrogen. which label belongs to the area marked z?

How do you identify the anode on a power source such as a battery? how do you identify the cathode? how are terms anion and cation?