Since tasting or touching the texture or surface could be deemed unsafe. It would be best to use a pH meter or litmus paper. pH meter will accurately determine pH. Litmus paper if red will be acidic and basic if blue. You can also perform conductivity test. Else, you can also perform hydrogen test.
Think about it. Considering ionisation energy is the energy required to remove a single electron from the valence shell of an element in the ground state, the less energy it takes, the easier it is to remove.
Answer:
F has the smallest atomic radius.
Explanation:
Atomic radius is one of the perIodic properties defined by the Periodic Table.
Atomich radius is the distance to the nucleus that comprises 95 % of the density electronic load. It can be defined as a function of the internuclear distance. Although this distance varies, depending on whether the atoms are linked by a chemical bond or simply in contact without forming link.
Atomic radius is a periodic property that increases by period (from the top to below) and decreases (from left to right) by group.
In the same group are O and F, so F < O
In the same group, we have S and Cl, so Cl < S
As Cl and F are in the same period, we define the atomic radius Cl > F and
S > Cl (In the same period)
The right way to order the elements are S > Cl > O > F