Which of the following are features of the electron cloud model of an atom?
a. an electron's exact position cannot be pinpointed.
b. the first electron shell holds 8 electrons.
c. all atoms contain two electron shells.

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?

What is the polyatamic ion of thiosulfate

Chlorophyll a had the molecular formula c55h72mgn4o5 how many atoms are in this molecule