Which of the following statements about transition metals is true? a.
They are never found uncombined in nature.
b.
They include familiar metals such as gold, silver, copper, and nickel.
c.
They are so soft that they can be cut with an ordinary knife.
d.
They are the most reactive of all the types of metals.

What is created when solids,liquids,an gases mix with one another

Aball with a mass of 275 g is dropped from rest, hits the floor and rebounds upward. if the ball hits the floor with a speed of 2.40 m/s and rebounds with a speed of 1.70 m/s, determine the following. (a) magnitude of the change in the ball's momentum (let up be in the positive direction.)

A1-lb collar is attached to a spring and slides without friction along a circular rod in a vertical plane. the spring has an undeformed length of 5 in. and a constant k =25 lb/ft. knowing that the collar is released from being held at a determine, the speed of the collar and the normal force between the collar and the rod as the collar passes through b.