It is not so much "pub" as Pb, the sign for the element lead. In Latin, the word for lead is plumbum. You've heard of plumbers? They are called that because water and sewer pipes used to be made of lead. (You know the lead pipe in Clue/Cluedo?) Lead has an atomic number of 82.
Ci means chlorine in the periodic table
Helium
Iodine
Oxygen,
what ploh does mean
calcium
a family of the periodic table is like a group of elements of the same type.
Er means erbium in the periodic table. It belongs to lanthanide series.
Mo stands for Molybednium in the periodic table. It is placed in group-6.
The only thing it might mean would be number, but that is usually no. and not NO. NO would be nitrogen oxide (nitric oxide), but that would NOT appear in the periodic table, as it is a compound, and only ELEMENTS appear in the periodic table.
Th is element number 90 on the periodic table It is thorium, it is in the Actinides, and it is radioactive
Periods are horizontal rows. 7 periods are present in modern periodic table.