OMTEX CLASSES SCIENCE AND TECHNOLOGY

SCHOOL OF ELEMENTS

FILL IN THE BLANKS

MATCH THE COLUMN

DEFINE

GIVE SCIENTIFIC REASONS [Textual]

Atomic size increases down the group

Metallic character decreases from left to right in a period

Elements in the same group show the same valency

GIVE SCIENTIFIC REASONS [Non Textual]

Chlorine is placed in VII A group in the modern periodic table.

Metallic character decreases across a period.

Group VII A elements are strong non-metals and group I A elements are

strong metals.

Non-metallic character increases across a period.

Atomic size decreases across a period.

The family of noble gases is called as zero group.

Valency varies gradually across a period.

OMTEX CLASSES SCIENCE AND TECHNOLOGY ANSWER THE FOLLOWING

How could the modern periodic table remove various anomalies of

Mendeleev's periodic table?

In modern periodic table, which are the metals, non metals and metalloids

among the first 20 elements?

What are the demerits of Mendeleev's Periodic table?

Define atomic size. How does it vary in a period and in a group?

Name three elements

The atomic number of an element X is 17. Predict :

Read the following descriptions and decide whether the element belongs to

metal or non-metal. Justify your answer.

How do you calculate valency of an element from its electronic configuration ?

What should be the position of Hydrogen in the Modern Periodic Table ?

Why?

How are isotopes of different elements placed in the Modern Periodic Table ?

Why is atomic number said to be a fundamental property?

Explain the features of Mendeleev's periodic table.

OMTEX CLASSES SCIENCE AND TECHNOLOGY Explain the zig-zag line in the periodic table. Explain the modern periodic table. Explain Newlands law of octaves giving examples.