In the nucleus of an atom, there are 18 protons and 20 neutrons. What are the atomic number and mass number of this isotope?

An astronomer wants to visualize the relative distances between planets in our solar system. A biologist wants to examine the branching of blood vessels within the body. A chemist wants to see the angles between bonds in a molecule.

A linear accelerator uses alternating electric fields to accelerate electrons to close to the speed of light.

Your family is moving to a new home. While lifting a box 1.5 m straight up to put it on a truck, you exert an upward force of 200 N. Calculate the amount of work you did. a) 300 J b) 201.5 J c) 198,5 J d) 133 J

A galaxy is observed to be spheroid and to have increasing stellar density toward the center. what is its galaxy classification?

Explain why the outer planets did not lose their lighter gases from their atmosphere.

Which of the following describes a characteristic of a series circuit? There is more than one path for the electrons to take. There is at least one power source and at least one receiver. All parts of the circuit are connected one after the next.

If you push against a stationary brick wall for several minutes, you do no work A. on the wall. B. at all. C. Both of the above. D. None of the above.

Awave is traveling through X. What can be known about X? It is empty space. It is any medium. It is a solid It is a liquid.

Who wrote the mayflower compact?

In the formula for specific heat, which quantity is measured in units of J/g•°C? a - c b - Q c - T d - m