(English Medium) ICSE Class 10 - CISCE Question Bank Solutions for Chemistry

Size of atom progressively becomes smaller when we move from sodium (Na) to chlorine (CI) in the third period of the periodic table?

Fill in the blank:

On moving across a period from right to left in the periodic table, the atomic size of the atom ___________.

Give reasons for the following:

The size of the anion is greater than the size of the parent atom.

Give reason for the following:

Argon atom is bigger than chlorine atom. 

Arrange the following in order of increasing radii:

CI^- , CI 

State which of the two a solution of HCl in water or in toluene is an electrolyte. Explain.

Is ammonia more dense or less dense than air?

What property of ammonia is demonstrated by the fountain experiment?

Ammonium salts decompose on heating. What other property do ammonium salts have in common?

State what you observe when a piece of moist red litmus paper is placed in a gas jar of ammonia.

Give two reactions to show reducing property of ammonia.

Name two gases which give dense white fumes with ammonia.

Name a metallic chloride soluble in ammonium hydroxide.

When an ammonium salt is warmed with a sodium hydroxide solution, a gas is evolved. State three ways in which you can identify this gas.

Complete the following equation. What property of ammonia is illustrated by the reaction given below.
2NH₃ + 3CuO →

Among the elements of the second period, Li to Ne, pick out the element with the largest atomic size

Fill in the blanks.
Size of the atoms ______ from left to right across a period and ______ on descending in a group of normal elements.

Arrange the following in increasing order of property indicated
 I, I⁺, I^- (atomic size)

Select the correct answer
Atomic radii of fluorine and neon in angstrom unit are

What happens to the atomic size of elements on moving from left to right in a period?