Answer:
Led is a light-emitting diode, a semiconductor diode that glows when a voltage is applied. So, there is always a sure result of whether a substance conducts electricity or not as the light glows. That is why it is a better option for testing conduction of electricity.
Explanation:
Reaction of sodium with water
Sodium metal reacts rapidly with water to form a colourless solution of sodium hydroxide (NaOH) and hydrogen gas (H2). The resulting solution is basic because of the dissolved hydroxide. The reaction is exothermic. During the reaction, the sodium metal may well become so hot that it catches fire and burns with a characteristic orange colour. The reaction is slower than that of potassium (immediately below sodium in the periodic table), but faster than that of lithium (immediately above sodium in the periodic table).
2Na(s) + 2H2O → 2NaOH(aq) + H2(g)
Here's an example of a bar graph.
Ggggggggggggggggggggggggggggggggggggggg