Science Olympiad Test: Periodic Classification of Elements- 1 - Class 10 MCQ

The difference between atomic numbers is 8.

Elements in a period have consecutive atomic numbers i.e., 34, 35, 36.

The first period contains 2 elements. The second period contains 8 elements. The third period contains 8 elements. Therefore, the first period contains 1−2 atomic number. The second period contains 3−10 atomic number. The third contains 11 to 18 atomic number. The fourth period contains 19 to 36 atomic number. 
So B, C, and D belong to the same period.

Elements of 2^nd period have smaller size than those of the corresponding elements of the 3rd period. Further is a period, halogen has the smallest size. Among Na, F, Mg and Al, F has the smallest size and hence it does not lose an electron easily.

Elements which differ in atomic numbers by 8 i.e., 9 (fluorine) and 17 (chlorine).

Larger the atomic radius of an element, more easily it can lose its valence electrons. K has the largest atomic radius, therefore it can lose on electron more easily.

All recognized living systems have an important ingredient in all organic molecules. Carbon is a non-metal that is tetravalent, which means it has four electrons available for covalent bonding. It is a member of group IV and has an atomic number of 6, i.e. 2,4. Because it is the first member of the family, it is known as the carbon family.

Elements with electronic configuration (2, 8) is an inert gas i.e., neon and hence belongs to group 18.

On moving left to right in a period atomic size decreases due to higher attraction. Thus the increasing order of atomic size for given elements is Na > Mg > AI > Si.

Oxide of Li is basic.