If an element with an atomic number of 51 and an atomic mass of 121, how many neutrons does it have?

Why are some rocks smooth and others rough?

Sound waves move the most slowly through? solids liquids or gases

To increase the brightness of a desk lamp, a student replaces a 50-watt incandescent lightbulb with a 100-watt incandescent lightbulb.

13. Sound waves can't travel through A. a solid. B. a liquid. C. an elastic material. D. a vacuum.

Two identical, unlabeled boxes are transported to an orbiting space station. The astronauts know that one box is filled with a light sample of ants for an experiment, and the other is filled with heavy tools for repairs.

The acceleration produced by a net force on a body is inversely proportional to the mass of the body. true or false

You throw a ball upward with an initial speed of 4.3 m/s. When it returns to your hand 0.88 s later, it has the same speed in the downward direction (assuming air resistance can be ignored).

Why are arrows of varying lengths used to represent forces?

At room temperature, most of the atoms of atomic hydrogen contain electrons that are in the excited states. A tube is filled with atomic hydrogen.

Acharged particle moving through a magnetic field at right angles to the field with a speed of 36.2 m/s experiences a magnetic force of 7.38x104 N.