What is the number of valence electrons in each of the main groups on the periodic table?

How does a hydroelectric power plant converts energy into energy.

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?

Using data from seismic waves, geologists have learned that earth’s interior is made up of several