Which element is less reactive, an element who's atoms have seven valence electrons or an element whose atoms have eight valence electrons? explain.

The earth is constantly spinning on its axis, like you might spin a basketball on your finger. it is this spinning of the earth that causes

Could someone . i have tried to solve myself but my calculation is off

On a frictionless air track, a blue glider with mass 0.200 kg is moving to the right with a speed of 8.00 m/s. it strikes a red glider that has mass 0.600 kg and that is initially at rest. after the collision, the blue glider is moving to the left with a speed of 3.00 m/s.(a) what are the magnitude and direction of the velocity of the red glider after the collision? (b) is this collision elastic?