Un catión tetravalente tiene 50 electrones, si la cantidad de neutrones excede en 20 a su número atómico; hallar su número de masa. a) 162 b) 128 c) 281 d) 234

__ _ _ _ _ is the process of removing earth materials from their original sites through weathering and transport and depositing the in another location. a. erosion b. sedimentation c. lithification d. dissolution

What is the ima of the 1 st class lever in the graphic given? 2 3 0.5

What is the number of moles of chemical units represented by 9.03x10^24? and how do i show work? (dumb it down )