Please could someone help me?

How many molecules are present in 3 mols of silicon dioxide (sio2)?

Need asap ‼️ 20 pts which gravitational force field diagram is drawn correctly? (answers in pictures below)

Which of the following situations is impossible? a) an object has velocity directed east and acceleration directed east. b) an object has zero velocity but non-zero acceleration. c) an object has constant non-zero velocity and changing acceleration. d) an object has velocity directed east and acceleration directed west. e) an object has constant non-zero acceleration and changing velocity.