Home Class 11 | Chemistry | Chapter 03 | Classification of Elements and Periodicity in Properties In 1800, only ....X.... elements were known. Here, X refers to (a) 63 (b) 31 (c) 114 (d) 92 In 1800, only ....X.... elements were known. Here, X refers to (a) 63 (b) 31 (c) 114 (d) 92 Ruhul Amin Alig Tags Class 11 | Chemistry | Chapter 03 | Classification of Elements and Periodicity in Properties Facebook Twitter Whatsapp Newer Older
