1. Sodium chloride (NaCl) commonly known as table salt, is the most common type of salt. What is the mass of 19.0 mol of sodium chloride (molar mass of sodium 22.99 g/mol and
chlorine 35.45 g/mol?

Because its reliable.   there is no pollution  the chances of a radiation leak is low

Ohm's law tells you that i = v/r where v is equivalent voltage and r is equivalent resistance of the circuit
since all circuits have the same voltage, your question is really asking which circuit has the lowest total resistance, since the lower the resistance, the higher the current
circuit a has a resistance of 5 ohms; circuit c is in series so has a resistance of 10 ohms; circuit b is in parallel and therefore has a resistance of 2.5 ohms (review your notes on adding resistances in parallel and series); therefore b has the highest current

  the answer is don't know.