||UNESCO inaugurated the celebration of 2019 as the International Year of the Periodic Table of Chemical Elements to celebrate its completion of how many years?
||What is the usual property of oxides of Groups 3 and 4?
||Basic and Acidic
||The element found maximum in the soil layer is –
||Which is present in the largest amount in terms of percent by mass in the earth’s crust?
||Which is the most abundant element after Oxygen?
||Which is the most common element in the Universe?
||Approximately how many different chemical elements exist on the earth?
||The chemical composition of a diamond is?
||Which element was first produced artificially?