Periodic table/ Mendeleev's periodic law/ modern periodic table/ Important questions related to inorganic chemistry/ periodic table

 Important questions related to inorganic chemistry/ periodic table

Q no 1. What is a periodic table?

      Ans; Periodic table is an arrangement of the elements by a symbol in the order of increasing atomic number. The important function of the periodic table is for the systematic organization of chemistry.

Q no 2. State Mendeleev’s periodic law.

Ans; The properties of elements are periodic functions of their atomic masses. If the elements are arranged on the basis of increasing atomic masses, some properties of elements are repeated after ha regular interval.

Q no 3. State Mosely’s modern law.

Ans; The properties of elements are a periodic function of increasing atomic number.

Q no 4. What is different between periodic and groups.

Periods	Groups
The horizontal rows of the periodic table are called periods. There are seven periods in the modern periodic table.	The vertical columns of the periodic table are called groups. There are 18 groups in the modern periodic table.

Q no 5. Write some characteristics of groups.

1. The valencies of all elements of the same group are the same.

2. All the elements of one group have the same physical and chemical properties.

3. All the elements of one group have the same number of outermost shell electrons.

4. Size of the atom increases from top to bottom in a group.

5. There are eighteen groups in the modern periodic table.

Q no 6. Write some properties of periods.

1. . There are seven periods in the periodic table.
2. 2. Size of an atom decrease from left to right in a period.
3. 3.  The number of outermost shell electrons is not the same in the elements of the period.
4. 4.  The period no tell us about the number of shells of elements of that period.

Q no 7. What is the diagonal relationship?

       Ans; When two elements show similarities in properties then this relationship is known as a diagonal relationship.

For Example; the relation of Li with Mg

Q no 8. What is the difference between transition elements and inner-transition elements?

Transition elements	Inner-transition elements
1. The elements in which two outermost subshells are partly filled while the remaining inner subshells are completely filled. 2. These elements have variable valencies. 3. Their valance electrons lie in the d sub-shell so these elements are called d-block elements.	·      The elements in which three outermost shells are partially filled while the remaining inner subshells are completely filled. ·      Their valance electrons lie in the f-subshell, so these elements belong to f- block elements. ·      Lanthanides and actinides are called f-block elements.

Q no 9. Write the difference between noble gases and representative elements.

Noble gases	Representative elements
The elements of the group no 18 are called noble gases. This group is also called the zero group. These elements have a complete outermost shell so these are very less reactive elements. All the other elements of the periodic table tend to attain the configuration of these elements.	These elements have completely filled inner subshells but outer subshells are partially filled. Their outermost electron lies between 1s2 to ns2p6. These elements belong to s-block as well as p-blocks. These are also called normal elements.