The relative atomic masses of tellurium ( $Te$ ) and iodine ( $I$ ) are 128 and 127, respectively. Why did this present a problem to Mendeleev when he was constructing his Periodic Table?

Important Questions on Periodicity

MEDIUM

AS and A Level

IMPORTANT

Chemistry for Cambridge International AS & A Level Coursebook with Digital Access (2 Years)>Chapter 10 - Periodicity>Question>Q 1

Why are the elements in Groups 1 and 2 known as '

s

-block elements', whereas those in Group 17 are called '

p

-block elements'?

MEDIUM

AS and A Level

IMPORTANT

Chemistry for Cambridge International AS & A Level Coursebook with Digital Access (2 Years)>Chapter 10 - Periodicity>Question>Q 2

By looking at the elements in Period 2 of the Periodic Table and using your knowledge of Period 3 elements, predict and explain the relative sizes of the atomic radii of lithium and fluorine.

MEDIUM

AS and A Level

IMPORTANT

Chemistry for Cambridge International AS & A Level Coursebook with Digital Access (2 Years)>Chapter 10 - Periodicity>Question>Q 2

By looking at the elements in Period 2 of the Periodic Table and using your knowledge of Period 3 elements, predict and explain the relative sizes of a lithium atom and its ion,

{Li}^{+}

.

EASY

AS and A Level

IMPORTANT

Chemistry for Cambridge International AS & A Level Coursebook with Digital Access (2 Years)>Chapter 10 - Periodicity>Question>Q 2

By looking at the elements in Period 2 of the Periodic Table and using your knowledge of Period 3 elements, predict and explain the relative sizes of an oxygen atom and its ion,

O^{2 -}

.

MEDIUM

AS and A Level

IMPORTANT

Chemistry for Cambridge International AS & A Level Coursebook with Digital Access (2 Years)>Chapter 10 - Periodicity>Question>Q 2

By looking at the elements in Period 2 of the Periodic Table and using your knowledge of Period 3 elements, predict and explain the relative sizes of a nitride ion