Q. 34.2( 187 Votes )
1. The modern periodic table was given by Henry Mosely. The modern periodic law states that periodicity of elements is a function of their atomic numbers.
2. The basic structure of the Modern Periodic Table is based on the electronic configuration of atoms of different elements consists of groups and periods, where the number of valence electrons determines the group and number of shells determines the period.
The given element’s electronic configuration is 2, 8, 4.This means that there are 14 electrons in this element. So,
a) So, the element belongs to the 3rd period and 4th group.
b) The element, therefore, is Silicon. Properties: Silicon is a metalloid and has a melting point if 1410oC. It is a poor conductor of electricity.
Rate this question :
Which of the following set of elements is written in order of their increasing metallic character?Evergreen Science
A non-metal A is an important constituent of our food and forms two oxides B and C. Oxide B is toxic whereas C causes global warming
(a) Identify A, B and C
(b) To which Group of periodic table A belongs?NCERT - Science Exemplar
Atomic number of a few elements are given below
(i) 10 (ii) 20
(iii) 7 (iv) 14
(a) Identify the elements
(b) Identify the period to which these elements belongNCERT - Science Exemplar
Arrange the following elements in the increasing order of their metallic character Mg, Ca, K, Ge, GaNCERT - Science Exemplar
Three elements A, B and C have 3, 4 and 2 electrons respectively in their outermost shell. Give the group number to which they belong in the Modern Periodic Table. Also, give their valencies.NCERT - Science Exemplar
Which of the following gives the correct increasing order of the atomic radii of O, F and N?NCERT - Science Exemplar
Properties of the elements are given below. Where would you locate the following elements in the Periodic Table?
(a) A soft metal stored under kerosene
(b) An element with variable (more than one) valency stored under water.NCERT - Science Exemplar
From the following elements:
4Be; 9F; 19K 20Ca
(i) Select the element having one electron in the outermost shell.
(ii) two elements of the same group.
Write the formula of and mention the nature of the compound formed by the union of 19K and element X(2,8,7).Science - Board Papers
Write the number of periods the Modem Periodic Table has. State the changes in valency and metallic character of elements as we move from left to right in a period. Also state the changes, if any, in the valency and atomic size of elements as we move down a group.Science - Board Papers