An atom with atomic number $20$ is most likely to combine chemically with the atom whose atomic number is

Following statements regarding the periodic trends of chemical reactivity of the alkali metals and the halogens are given. Which of these statements gives the correct picture?

The correct sequence of acidic character is:

Which of the following orders is correct $-$

In the modern periodic table,the acidic nature of oxides:

Given below are two statements :
Statement $I$ : An element in the extreme left of the periodic table forms acidic oxides.
Statement $II$ : Acid is formed during the reaction between water and oxide of a reactive element present in the extreme right of the periodic table.
In the light of the above statements,choose the correct answer from the options given below :