Which of these belong to same group: Element Atomic number A 2 B 10 C 5

Element Atomic number Electronic configuration A 2 2 B 10 2 , 8 C 5 2 , 3 Valence electrons in an atom defines the group it belongs to. Since the electronic configuration of elements A and B shows that their valence shells have complete duplet and octet respectively. It represents the configuration of noble gas. Hence, element A and element B belong to same group i.e. group 18 .

Which of these belong to same period: Element Atomic number A 2 B 10 C 5

Electronic configurations of the elements are as follows: Element Atomic number Electronic configuration A 2 2 B 10 2 , 8 C 5 2 , 3 Number of shells in an atom defines its period in the periodic table. Element B and element C both have their last electron in shell L . Hence, these two elements lie in the same period that is period 2 .

E M B I B E

MODERN'S ABC+ OF SCIENCE CHEMISTRY>Chapter 5 - Periodic Classification Of Elements>Revision Exercise>Q 12

MEDIUM

10th CBSE

IMPORTANT

Earn 100

Explain why the properties of the $8^{th}$ element are repeated in case of elements arranged in $2^{nd}$ and $3^{rd}$ period of long form of the periodic table.

Important Questions on Periodic Classification Of Elements

MEDIUM

10th CBSE

IMPORTANT

MODERN'S ABC+ OF SCIENCE CHEMISTRY>Chapter 5 - Periodic Classification Of Elements>Revision Exercise>Q 13

Name two elements whose atoms are readily converted to unipositive ion.

MEDIUM

10th CBSE

IMPORTANT

MODERN'S ABC+ OF SCIENCE CHEMISTRY>Chapter 5 - Periodic Classification Of Elements>Revision Exercise>Q 14

Argon has atomic number 18 and belongs to third period and eighteenth group. Predict the group and period for the elements having atomic number 17 and 19 respectively.

MEDIUM

10th CBSE

IMPORTANT

MODERN'S ABC+ OF SCIENCE CHEMISTRY>Chapter 5 - Periodic Classification Of Elements>Revision Exercise>Q 15

Which of these belong to same group:

Element	Atomic number
$A$	$2$
$B$	$10$
$C$	$5$

MEDIUM

10th CBSE

IMPORTANT

MODERN'S ABC+ OF SCIENCE CHEMISTRY>Chapter 5 - Periodic Classification Of Elements>Revision Exercise>Q 15

Which of these belong to same period:

Element	Atomic number
$A$	$2$
$B$	$10$
$C$	$5$

MEDIUM

10th CBSE

IMPORTANT

MODERN'S ABC+ OF SCIENCE CHEMISTRY>Chapter 5 - Periodic Classification Of Elements>Revision Exercise>Q 16

What is periodicity? What is the cause of periodicity?

HARD

10th CBSE

IMPORTANT

MODERN'S ABC+ OF SCIENCE CHEMISTRY>Chapter 5 - Periodic Classification Of Elements>Revision Exercise>Q 18

What is the basic difference in the electronic configurations of the elements belonging to group 1 and group 17? How do these help to explain different properties of the elements?

MEDIUM

10th CBSE

IMPORTANT

MODERN'S ABC+ OF SCIENCE CHEMISTRY>Chapter 5 - Periodic Classification Of Elements>Revision Exercise>Q 19

What is metallic character? How does it change in a period?

MEDIUM

10th CBSE

IMPORTANT

MODERN'S ABC+ OF SCIENCE CHEMISTRY>Chapter 5 - Periodic Classification Of Elements>Revision Exercise>Q 19

How do atomic radii change in a period and in a group?