Chemical reactions can be recognized by the presence of heat, light, or gas formation. The ultimate outcome for any chemical reaction is the change from a solid to a liquid. presence of sound. formation of a new chemical substance.

While goofing off at the ice skating rink, a student takes off her shoes and places each of them on the ice. her friend, a hockey player, then shoots a hockey puck at each shoe. the first puck immediately comes to rest after it collides with the left shoe. the second puck rebounds after it collides with the right shoe. if each hockey puck has the same incoming speed, which shoe has greater speed after the collision? the right shoe. both shoes have the same speed. the left shoe.

When you turn on a battery-operated device, an electrical circuit is

What is the speed of an object at a given moment?