In the formula X20, the symbol X could represent an element in Group A) 1
B) 2
C) 15
D) 18​

Which function is performed by earths atmosphere? a. ultraviolet rays are prevented from reaching the ozone layer. b. earths temperature is raised and moderated by trapping in heat c. charged particles from the sun are prevented from reaching earth. d. magnetic charges from space are prevented from reaching earths surface.

What is the equilibrium constant of aa+bb=cc+dd

Design techniques and materials that reduce the negative environmental impact of a structure are referred to as