Answer:
The horizontal rows/lines on the periodic table are called periods.
Explanation:
A little trick i learnt: The atomic number reflects how many electrons there are, and there must be an equal charge. therefore, there are the same amount of protons as there are electrons. so if it has 81 protons, we look for number 81 in the periodic table, Thallium
Though there's no question in the statement above I would assume that you are asking about the pH of the water that is acidic. The correct statement would be:
Any liquid that has a pH less than 7 is called acidic, a pH above 7 is basic or alkaline.
The water in the swimming pool has a high acid concentration due to the chlorine which causes the effect of redness in the eyes.
