Science : Ch 05 – Periodic of Classification of Elements

Which of the following affirmation about the modern periodic table are inappropriate?

1. The elements in the modern periodic table are arranged on the basis of their decreasing atomic numbers
2. The elements in the modern periodic table are arranged on the basis of their increasing atomic masses.
3. Isotopes are placed in adjoining group(s) in the periodic table.
4. The elements in the modern periodic table are arranged on the basis of their increasing atomic number

The elements A, B, C, D and E have atomic number 9, 11, 17, 12 and 13 respectively. Which pair of elements belongs to the identical group?

An element which is a crucial constituent of all organic compounds belongs to:

As claimed by Mendeleev’s periodic law, the elements were arranged in the periodic table in the order of:

Organise the following elements in the order of their decreasing metallic character Na, Si, Cl, Mg, Al:

Which among the following elements has the largest atomic radii?

Which of the following elements does not lose an electron with ease?

Which of the following are the characteristics of isotopes of an element?

1. Isotopes of an element have the same atomic masses.
2. Isotopes of an element have the same atomic number
3. Isotopes of an element show the same physical properties.
4. Isotopes of an element show the same chemical properties.

Three elements B, Si and Ge are:

The element with atomic number 14 is hard and forms acidic oxide and a covalent halide. To which of the following classification does the element belong?

Arrange these elements in decreasing order of their atomic radii

Arrange these elements in increasing order of their atomic radii

Why does atomic radius decreases as we move from left to right in a period

The metallic character vary across the period

The formulae of chlorides of Eka-aluminium, the elements predicted by Mendeleev.