A sample of a radioactive elements must contain atoms

A.

with a stable nuclei

B.

with unstable nuclei

C.

in the excited state

D.

in the ground state

What are the three most influential variables that affect electrical force?

How does Earth's atmosphere make conditions on Earth suitable for living things?

The electromagnetic wave that delivers a cellular phone call to a car has a magnetic field with an rms value of 1.90 10-10 T. The wave passes perpendicularly through an open window, the area of which is 0.20 m2.

A ray of light is incident on a flat surface of a block of polystyrene, with an index of refraction of 1.49, that is submerged in water. The ray is split at the surface, where the angle of refraction of the transmitted ray is 19.1°.

A grindstone increases in angular speed from 6.00 rad/s to 12.20 rad/s in 16.00 s. Through what angle does it turn during that time if the angular acceleration is constant?

What is the name of the fine soil particles deposited by rivers?

A ball of mass 200 g rolls along the ground at a speed of 5.2m/s. calculate the kinetic energy of the ball. Give answer to one decimal place.

A light bulb that is connected to a 120 V source drawers 1.7 A. What is the resistance of the light bulb? A. 14 B. 71 C. 200 D. 0.014 E. 0.0

Which of the following is an example of heat transfer through radiation? A. A pot of soup warming on a hot burner. B. A crayon melting on a hot sidewalk. C. Beach sand getting warmed by the sun. D. An egg getting cooked in a pot of boiling water.

Which of the following best describes each particle? A. Protons are negative, neutrons are neutral, and electrons are positive. B. Protons are neutral, neutrons are positive, and electrons are negative. C.