There are 4 significant figures! Start counting after the first non-zero digit :)
Hope this helps.
Answer:
in disodium phosphate = 4 oxygen atoms
in phosphoric acid = 1 oxygen atom
We know that the element Z = 119 would be placed right below the Fr, in the column of the alcaline metals.
We also know that the trend in the electronegativity is to decrease when you go up-down ia group.
The known electronegativities of the elements of this group are:
Li: 0.98
Na: 0.93
K: 0.82
Rb: 0.82
Cs: 0.79
Fr: 0.70
Then the hypotetical element Z = 119 would probably have an electronegativity slightly below 0.70, for sure in the range 0.60 - 0.70.
The Arrhenius definition of acid-base reactions, which was devised by Svante Arrhenius, is a development of the hydrogen theory of acids. ... An Arrhenius base is a substance that dissociates in water to form hydroxide (OH -) ions. In other words, a base increases the concentration of OH - ions in an aqueous solution.
