Write the name and deduce the atomic number of the following element
i. The second alkali metal
ii. The fourth noble gas
iii. The third halogen
iv. The first transition element

Name the third chalcogen and fifth noble gas

Lanthanoids and actinoids are placed in separate rows at the bottom of the periodic table. Explain.

Helium has a electronic configuration of 1s² but placed in p block in group 18. Justify.

Describe in brief Lothar Meyer's classification of elements.

Explain classification of elements based on Newland's law of Octaves.

Justify the given statement with suitable examples "the properties of the elements are a periodic function of their atomic numbers".

State the findings of modern periodic law.

State Mendeleev's period law.

What are the demerits of long form periodic table.

What are transuranium elements?

What are transfermium elements?

Period 3 of the modern periodic table has only eight elements. Explain.

Predict the position of the element having an electron configuration(n -1) d¹ ns² for n = 4.

How many elements can be accommodated in the long form of the periodic table? Explain.

Name the p block elements that exist as liquids at room temperature.

What are representative elements?

What are metalloids? Give example.

The number of elements in the first period is only 2. Give reason.

The elements Z = 117 and 120 have not yet been discovered. In which family/group would you place these elements and also give the electronic configuration in each case.

Arrange the following elements in the increasing order of metallic character: Si, Be, Mg, Na, P.

To which block does the element with configuration 3d¹⁰ 4s² belong?

Predict the periods and blocks to which each of the following elements belongs?
(i) ₁₃Al
(ii) ₂₄Cr
(iii) ₂₉Cu
(iv) ₁₁Na

Why are noble gases chemically inert?

Why d-block elements are known as transition element?

Rn (Z = 86) is the last noble gas discovered. Predict what will be the atomic number of the next noble gas to be discovered. Write its symbol.

What are inner transition elements?

In terms of electronic configuration what does elements of given period and a group have in common?

All transition elements are d-block elements, but all d-block elements are not transition elements. Explain.

Write the name and atomic number of the following elements.
(i) The first halogen
(ii) The third alkali metal
(iii) The fourth alkaline earth metal
(iv) The sixth element of the second transition series
(v) The second inner transition element
(vi) The fifth noble gas.

Noble gases have almost zero electron affinity give reason.

Why electron affinity of fluorine is less than that of chlorine?

Which among the halogens would you expect to have the least electronegativity and why?

Arrange the following elements in the increasing order of non-metallic character. B, C, Si, N, F

Give reason for the following statements
Halogens act as good oxidising agents.

The second electron affinity of O is positive, whereas first is negative. Give reason.

Define metallic radius.

Define covalent radius.

Radius of a cation is smaller than the parent atom. Account for the following.

Explain the size of Cl^- >Na⁺.

Define periodicity.

Out of Na and Mg, which has higher second ionisation energy?

Noble gases have maximum ionisation energy. Justify.

Which of the following species will have the largest and smallest size Mg, Mg²⁺, AI, Al³⁺? Give reason.

The size of Cl^- = 1.81Å and CI = O.99Å. Explain.

How does the shielding effect caused by inner electrons affect the ionisation energy?

Larger the size of the atom, lesser is the ionisation energy. Explain.

Define Ionization enthalpy.

(i) Which is largest in size Cu⁺, Cu²⁺ or Cu and why?
(ii) Which element in periodic table has highest ionisation energy (IE)?
(iii) Which element is more metallic Mg or Al and why?

Briefly outline the characteristics of modem periodic table

Write the electronic configuration of the elements whose atomic numbers are given below: (A) 35,(B) 18, (C) 28, (D) 38. Also predict period, group, and block to which they belong.

From the inter nuclear distance between two atoms A and B (d_A-B) and from their electronegativities, how will you find the covalent radius of atom A + B?

The inter nuclear distance between hydrogen and chlorine, is 1.28A and the covalent radius of chlorine is 0.99A. The electronegativity values of chlorine and hydrogen are 3 and 2.1 respectively. Determine the covalent radius of hydrogen atom

Explain why cations are smaller and anions are larger than their parent atoms?