Modern periodic table is used to predict:

P — Whether an element is solid, liquid or gas.

Q — The nature of chemical bonds formed when elements combine.

R — The formula of the compound formed when elements combine.

1. Only P
2. Only Q
3. Only R
4. Both Q and R

Assertion (A): Noble gases do not combine with other elements.

Reason (R): The outermost orbit of noble gases are complete, they have a stable electronic configuration.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Assertion (A): Chlorine with atomic number 17 is placed in group 17 and period 3.

Reason (R): The number of shells signifies a period, while the number of valence electrons indicates the group.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Assertion (A): ¹⁹Fluorine, ³⁵Chlorine and ⁸⁰Bromine do not constitute a Döbereiner's triad.

Reason (R): Atomic mass of chlorine is not the average mass of Fluorine and Bromine.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.