Barium is Group
I
I
, Period 6,
Z
=
56
. The last closest Noble Gas is
Z
=
54
. This is xenon.
Answer:
A. Similar elements have such different masses that this would lead to a completely random arrangement of elements.
Explanation:
Because it is the number of protons, which is identical to the atomic number, that separates different elements from each other, not the atomic mass.
Because the solid is soluble in water, it cannot be calcium fluoride.
This leaves us with either silver fluoride or potassium bromide, as both are soluble in water.
Upon addition of sodium sulfate, a white precipitate forms, confirming that the substance was silver fluoride as the precipitate are of silver sulfate.
