A locomotive pulling a train out from one station travels along a straight horizontal track towards another station. The following describes how the velocity of the train varies with time over the whole journey. It started from rest and gain a speed of 40 ms-1 in 2 s. It then traveled at this speed constantly for 10 s. Finally, it decelerates and reaches the other station within 2 seconds.

Many free radicals combine to form molecules that do not contain any unpaired electrons. the driving force for the radical–radical combination reaction is the formation of a new electron‑pair bond. consider the chemical equation. n(g)+no(g)⟶nno(g) n(g)+no(g)⟶nno(g) write lewis formulas for the reactant and product species in the chemical equation. include nonbonding electrons. n(g)n(g) select draw rings more erase select draw rings more erase select draw rings more erase n no(g)