Atoms are the particles that all matter is made from. When two or more kinds of atoms combine, they form . A. pure elements B. molecules C. metals D. the periodic table

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.