Modern Periodic Law

Q.

How many Gaseous Elements are there in Periodic Table

Q.

Which is the most reactive nonmetal?

Q.

Define representative elements?

Q.

What does the group number mean on the periodic table of elements?

Q.

F < Cl < Br < I is the correct arrangement in terms of :

1. Electronegativity

2. Atomic size

3. Electron affinity

4. Reactivity

Q.

The atom of an element has 20 protons, 20 electrons, and 20 neutrons :

(a) What is the atomic number of the element?

(b) What is the mass number of the element?

(c) Name the element.

(d) Write the electronic configuration of the element.

Q.

Write down the chemical formula of Zinc.

Q.

In modern periodic table nitrogen is placed just before oxygen in the 2nd period because:

1. The given statement is false. In the modern periodic table oxygen is placed before nitrogen.

2. Oxygen has one more proton in its nucleus than nitrogen.

3. Nitrogen has bigger atomic radius than oxygen.

4. Oxygen is more electronegative than nitrogen.

Q.

The electronic configuration of an element is 2, 8, 7:

1. What is the group number of T?
2. What is the period number of T?
3. What is the valency of T?
4. Is T a metal or non-metal?
5. How many valence electrons are there in the atom of T?

Q.

Which of the following elements is used to make pencil lead?

1. Carbon

2. Boron

3. Phosphorous

4. Lead

Q.

Why is CuSO₄ the expected formula of Copper Sulphate and not Cu₂SO₄ when Copper has variable valency of Cu⁺ and Cu²⁺ ; Here the higher valency is used for the salt.

However in the case of Iron Sulphate the expected formula is FeSO₄ and not Fe₂(SO₄)₃ eventhough Iron also has variable valency of Fe²⁺ and Fe³⁺ ; Here the lesser valency is used for the salt.

Q.

In the modern periodic table, the elements are arranged on the basis of their increasing atomic number.

1. True

2. False

Q.

Name the longest period in the modern periodic table.

Q. Who is the father of period table.

Q.

Phosphorus is a metal or nonmetal?

Q.

Why are elements belonging to group 18 called noble gas elements?

Q. Alkaline earth metals have valency 2. This means that their position in the modern periodic table is in .....

1. 
   d-block
2. 
   Group 2
3. 
   Group16
4. 
   Period 2

Q.

What are typical or representative elements in the modern periodic table?

Q. Correct order of third ionization energy of Boron carbon nitrogen and Oxygen will be

Q.

Define the modern periodic law. Why was it necessary to change the basis of classification?

Q. Since electron affinity of third period is more than that of second period then why does electron affinity of lithium is more than sodium?

Q.

The formula of ion formed by an element A is $A^{+2}$. The element A can probably belong to which of the following groups?

1. IIIA

2. VIIA

3. IIA

4. IA

Q.

An element $E$ combines with oxygen to form an oxide $E_{2}O$ which is good conductor of electricity. Give the following information:

1. How many electron will be present in the valence shell of element $E$?
2. Write the formula of the compound formed when the element $E$ combines with chlorine.

Q. What is modern periodic law?

Q.

What is the periodic table of Elements?

Q.

How to find neutron?

Q.

A recently discovered isotope of the noble element oganesson (symbol ‘Og’) has electronic configuration 2, 8, 18, 32, 32, 18, 8 and mass number 294.Calculate the number of electrons, protons and neutrons in its atom.

Q. The problem with elements being arranged in the increasing order of atomic masses is that the atomic mass does not increase in a regular manner in going from one element to next. So, it is not possible to predict how many elements could be discovered between the elements. This is why in the Modern Periodic Table elements are arranged according to their ___.

Q. Electronic configuration of an element is $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{5}4s^1$. Total number of electrons present in M shell of this element is:

1. $1$
2. $5$
3. $12$
4. $13$

Q.

The atomic particle whose number in the atoms of an element always remains the same and which forms the real basis for the modern classification of elements is :

(a) electron (b) proton (c) neutron (d) meson