Why the table perdioc has 3 columns in its group 8 ,
i need reference about that please

Although respiratory organs vary across different organisms, they all contain respiratory surfaces that have a large surface area and are extremely thin. explain why having an extremely thin respiratory surface with a large surface area is advantageous for the process of gas exchange

Draw the lewis dot structure for each of the following polyatomic ions

How do dying stars contribute to the formation of planets