MEDIUM
10th Maharashtra Board
IMPORTANT
Earn 100

What are the smallest particles of matter called?

Important Questions on Periodic Classification of Elements

MEDIUM
10th Maharashtra Board
IMPORTANT
Science and Technology Standard Ten Part - 1>Chapter 2 - Periodic Classification of Elements>Can you recall?>Q 4
What is the difference between the molecules of elements and compounds?
MEDIUM
10th Maharashtra Board
IMPORTANT
Science and Technology Standard Ten Part - 1>Chapter 2 - Periodic Classification of Elements>Can you tell?>Q 5

Identify Dobereiner’s triads from the following groups of elements having similar chemical properties.
1. Mg (24.3), Ca (40.1), Sr (87.6)

2. S(32.1), Se(79.0), Te(127.6)

3. Be(9.0), Mg(24.3), Ca(40.1)

HARD
10th Maharashtra Board
IMPORTANT
Science and Technology Standard Ten Part - 1>Chapter 2 - Periodic Classification of Elements>Think about it>Q 1
There are some vacant places in Mendeleev’s periodic table. In some of these places, the atomic masses are seen to be predicted. Enlist three of these predicted atomic masses along with their group and period.
MEDIUM
10th Maharashtra Board
IMPORTANT
Science and Technology Standard Ten Part - 1>Chapter 2 - Periodic Classification of Elements>Think about it>Q 2
Due to uncertainty in the names of some elements, a question mark is indicated before the symbol in Mendeleev’s periodic table. What are such symbols?
HARD
10th Maharashtra Board
IMPORTANT
Science and Technology Standard Ten Part - 1>Chapter 2 - Periodic Classification of Elements>Use your brain power
Chlorine has two isotopes, viz, Cl-35 and Cl-37. Their atomic masses are 35 and 37 respectively. Their chemical properties are the same. Where should these be placed in Mendeleev’s periodic table? In different places or in the same place?
HARD
10th Maharashtra Board
IMPORTANT
Science and Technology Standard Ten Part - 1>Chapter 2 - Periodic Classification of Elements>Use your brain power>Q 1

Write the molecular formulae of oxides of the following elements by referring to the Mendeleev’s periodic table.

Na, Si, Ca, C, Rb, P, Ba, Cl, Sn.

HARD
10th Maharashtra Board
IMPORTANT
Science and Technology Standard Ten Part - 1>Chapter 2 - Periodic Classification of Elements>Use your brain power>Q 2

Write the molecular formulae of the compounds of the following elements with hydrogen by referring to the Mendeleev’s periodic table.

C, S, Br, As, F, O, N, Cl.

MEDIUM
10th Maharashtra Board
IMPORTANT
Science and Technology Standard Ten Part - 1>Chapter 2 - Periodic Classification of Elements>Use your brain power>Q 1

Position of the elements in the periodic elements.

How is the problem regarding the position of cobalt 59Co and nickel 59Ni in Mendeleev’s periodic table resolved in the modern periodic table?