How do chemical reactions impact our local water supply ?

There are main groups in the modern periodic table of elements

Astudent carefully transfers 30 g of water and 30 g of alcohol in a glass tube, forming two layers and filling the tube completely. after sealing the tube, the student mixes the solutions, and notices a bubble that forms in the tube. what is the mass of the contents in the glass tube after mixing?

Which fact represents evidence for the big bang theory?