It is the 4th one that is correct and balanced
⇒Answer:
When the pH sensor hits pH=7.
⇒Explanation:
Because pH=7 is the indicator that the acid and alkali have been neutralized.
The most reactive metal on the periodic table is Francium, However, Francium is an artificial element and only minimal quantities have been produced, so for all practical purposes, the most reactive metal available is Cesium, in the alkali metal family.
ANSWER In theory, Francium, in practice the Cesium
A physical property is a quality or condition of a substance that can be observed or measured without changing the substance's composition. a chemical property is the ability of a substance to undergo a specific chemical change.