CHEMISTRY CH12 Periodic Classification of Elements Science - CHEMISTRY CH12 Periodic Classification of Elements

Elements in the modern periodic table are arranged in ______groups and______ periods.

Modern periodic law states that the physical and chemical properties of elements are the periodic functions of their ______.

If Dobereiner is related with ‘law of triads’, then Newlands is related with ______.

If the electronic configuration of an element is 1s2 2s2 2p6 3s2 3p1’then it will occupy ……………… block of the periodic table.

Which of the following metal (s) do not react with water?

Statement: Elements in a group generally possess similar properties but elements along a period have different properties.

Reason: The difference in electronic configuration makes the element differ in their chemical properties along a period.

• Statement is true and reason explains the statement.

• Statement is false but the reason is correct.

Assertion (A): Non-metals are electronegative. Reason (R) : Non-metal losë electrons to form cation.

(A) : Noble gases are chemically inert in nature. Reason (R) : Noble gases have stable electronic structures.

Assertion (A): Group 2 elements in the modem periodic table are called alkaline earth metals. Reason (R): The oxides of group 2 elements produce alkaline solutions when they are dissolved in water.

State any five features of modern periodic table.

What are the limitations of Mendeleev's periodic table?

Group 3-12 elements in the modern periodic table are called d block elements.

d-block elements are called transition elements.

Group 1 (except hydrogen) elements are called alkali metals.

Match the following.

1.	Triads	Newlands
2.	Alkali metal	Calcium
3.	Law of octaves	Henry Moseley
4.	Alkaline earth metal	Sodium
5.	Modern Periodic Law	Dobereiner

Symbol	Atomic No.	Electronic Configuration
1) He	2	?
2) Ne	?	2,8
3) Ar	?	2, 8,8
4) Na	11	?

 

to match:

Group in the modern periodic table	Families
a) 1	?
b) ?	Transition metals
c) ?	Boron family
d) 15	?
e) 17	?

List the features of Mendeleev’s Periodic Table.

Explain the position of hydrogen in the periodic table.

Write the advantages of the Modern Periodic Table.

List the advantages of alloys.

Example for liquid metal is ______.

The basis of the classifications proposed by Dobereiner, Newlands and Mendeleev was ______.

Noble gases belong to______ group of the periodic table.

In Dobereiner’s triads, the atomic weight of the middle element is ______ the of the atomic masses of 1st and 3rd elements.

Elements are placed in periods based on the number of ……………… in their atoms.

What are groups and periods in the modern periodic table?

State modern periodic law.

How are elements grouped into various families in the periodic table?

Complete the following triads by inserting the missing elements.a) Cl, ………., Ib) Li, ………, Kc) Ca, …………, Ba

Relate the names of the following scientists with the statements given below. (Mendeleev, Newlands, Dobereiner).a) Arranged elements into groups containing three elements each.b) Arranged elements in a group of seven with increasing atomic masses and eighth elements with similar properties kept below the first like eight note in an act of music.c) Arranged elements in the increasing order of atomic mass

State whether true or false. If false, correct the statement.

Group 17 elements are named as Halogens.

• True

• False

State whether true or false. If false, correct the statement.

Lanthanides and actinides are kept at the bottom of the periodic table because they resemble each other but they do not resemble with any other group elements.

• True

• False

State whether true or false. If false, correct the statement.

Alloys bear the characteristics of both metals and nonmetals.

• True

• False

State whether true or false. If false, correct the statement.

Metals can gain electrons.

• True

• False

State whether true or false. If false, correct the statement.

Newlands’ periodic table is based on atomic masses of elements and modern periodic table is based on atomic number of elements.

• True

• False