Class 10 Science-1 Chapter 2 Periodic Classification of Elements
Class 10 Science-1 Chapter 2 Periodic Classification of Elements Periodic Classification Of Elements Question 1. Rearrange the columns 2 and 3 so as to match with the column 1. Answer: Column 1 Column 2 Column 3 i. Triad Average of the first and the third atomic mass Dobereiner ii. Octave Properties of the eighth element similar to the first Newlands iii. Atomic number Positive charge on the nucleus Moseley iv. Period Sequential change in molecular formulae Mendeleev v. Nucleus Concentrated mass and positive charge Rutherford vi. Electron Lightest and negatively charged particle in all the atoms Thomson Question 2. Choose the correct option and rewrite the statement: (a) The number of electrons in the outermost shell of alkali metals is……. (a)