3. Which of the scenarios is best for hand-picking concentration? a) When the ores are good conductors of electricity b) When the impurities can be distinguished from the ore by the naked eye c) When either the ore or the impurities are magnetic d) When the ore particles are heavier than the impurities
Answer: b Explanation: It is vital for contaminants to be easily discernible from ore particles when concentration is done by hand picking. The ore is deemed to be pure if these contaminants can be seen with the naked eye. The ore is said to be suitable for concentration by hand picking.
