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

Both Q and R Reason Modern periodic table can be used to predict nature of chemical bond, formula of compound formed and properties of that compound.

Look at the periodic table given below and answer the following questions.
Groups I II III IV V VI VII VIII
Oxide:
Hydride: R₂O
RH RO
RH₂ R₂O₃
RH₂ RO₂
RH₄ R₂O₅
RH₃ RO₃
RH₂ R₂O₇
RH RO₄

Periods
↓ A B A B A B A B A B A B A B Transition
Series
1 H
1.008
2 Li
6.939 Be
9.012 B
10.81 C
12.011 N
14.007 O
15.999 F
18.998
3 Na
22.99 Mg
24.31 Al
29.98 Si
28.09 P
30.974 S
32.06 Cl
35.453
(I) This table was given by:
Newland
Döbereiner
Mendeleev
Moseley
(II) According to this periodic table, the formula of the oxide of nitrogen is:
N₂O₃
NO
N₂O₅
N₂O₇
(III) The defect(s) of this periodic table is/are:
P — Anomalous pairs
Q — Separation of chemically similar elements.
R — Grouping of chemically dissimilar elements.
Only P
Both Q and R
Both P and Q
P, Q and R

Groups	I	II	III	IV	V	VI	VII	VIII
Oxide: Hydride:	R₂O RH	RO RH₂	R₂O₃ RH₂	RO₂ RH₄	R₂O₅ RH₃	RO₃ RH₂	R₂O₇ RH	RO₄
Periods ↓	A B	A B	A B	A B	A B	A B	A B	Transition Series
1	H 1.008
2	Li 6.939	Be 9.012	B 10.81	C 12.011	N 14.007	O 15.999	F 18.998
3	Na 22.99	Mg 24.31	Al 29.98	Si 28.09	P 30.974	S 32.06	Cl 35.453