Question

give the structure of modern periodic table​

Answer 1

Answer:

n the modern periodic table, the elements are arranged in the order of their inreasing atomic number. In the modern periodic table there are seven horizontal rows called periods and eighteen vertical columns (1 to 18) called groups. The arrangement of the periods and groups results into formation of boxes.

Answer 2

Explanation:

Structure of the modern periodic table: Periodic Table: It is the table of chemical elements arranged in order of atomic number such that elements with similar atomic structures appear in the vertical columns.

The Modern periodic law states that The chemical and physical properties of elements are a periodic function of their atomic numbers. The modern periodic table is based on the modern periodic law.

Main features:

Groups - There are 18 vertical columns in the periodic table. Each column is called a group. All elements in a group have similar chemical and physical properties because they have the same number of valence electrons.

Periods - In periodic table elements are arranged in a series of rows. Elements of the same period have the same number of electron shells.

Classification of elements:

Group 1 contains alkali metals (Li,Na,K,Rb,Cs and Fr).

The alkaline earth metals are metallic elements found in the group 2 of the periodic table.

Elements present in groups 3 to 12 in the middle of the periodic table are called transition elements. In the transition elements, valence electrons are present in more than one shell.

Group 18 on extreme right side position contains noble gases (He,Ne,Ar,Kr,Xe and Rn). Their outermost shell contains 8 electrons except He as its outermost shell is K shell and it can hold only 2 electrons.

Inner transition elements:

14 elements with atomic numbers 58 to 71(Ce to Lu) are called lanthanides and they are placed along with the element lanthanum (La), the atomic number 57 in the same position (group 3 in period 6) because of the very close resemblance between them.

14 elements with atomic numbers 90 to 103(Th to Lr) are called actinides and they are placed along with the element actinium (Ac), the atomic number 89 in the same position (group 3 in period 7) because of the very close resemblance between them.