Combining which of the following substances with germanium will cause the germanium to emit free electrons?

A. Bismuth

B. Gallium

C. Aluminum

D. Indium

In a certain material there is a current of 16 A flowing through a surface to the right, and there is an equal amount of positive and negative charge passing through the surface producing the current.

What is rarefraction

A child on a playground swing is swinging back and forth (one complete oscillation) once every four seconds, as seen by her father standing next to the swing. At the same time, a spaceship hurtles by at a speed close to the speed of light.

What is the smallest distance between the speakers for which the interference of the sound waves is destructive?

What organelles is found in most plant cells, but is never found in animal cells?

Which, if any, of the heat engines violate (s) the second law of thermodynamics?

The ball is moving at a constant speed of 0.5 m/s for 2.3 seconds how far does it go?

Which of these is a mixture? calcium carbon dioxide salt water potassium

A train travels 80 kilometers in 2 hours, and then 79 kilometers in 4 hours. What is its average speed?

What does it mean when we say science is a cycle?