Describe the structure of an atom.
a) the nucleus is the dense center of the atom composed of protons and neutrons. surrounding the nucleus is an electron cloud composed of electrons.
b) the nucleus is the dense center of the atom composed of electrons and neutrons. surrounding the nucleus is an electron cloud composed of protons.
c) the electron cloud is the dense center of the atom composed of electrons. surrounding the electron cloud is a nucleus composed of protons and neutrons.
d) the electron cloud is the dense center of the atom composed of protons and neutrons. surrounding the electron cloud is a nucleus composed of electrons.

As part of your daily workout, you lie on your back and push with your feet against a platform attached to two stiff springs arranged side by side so that they are parallel to each other. when you push the platform, you compress the springs. you do an amount of work of 79.0 j when you compress the springs a distance of 0.230 m from their uncompressed length. (a) what magnitude of force must you apply to hold the platform in this position? (b)how much additional work must you do to move the platform a distance 0.230 m farther? (c) what maximum force must you apply to move the platform a distance 0.230 m farther?

What is the single most important equation in all of physics?

Assume that two of the electrons at the negative terminal have attached themselves to a nearby neutral atom. there is now a negative ion with a charge -2e at this terminal. what are the electric potential and electric potential energy of the negative ion relative to the electron? the electric potential and the electric potential energy are both twice as much. the electric potential is twice as much and the electric potential energy is the same. the electric potential is the same and the electric potential energy is twice as much. the electric potential and the electric potential energy are both the same. the electric potential is the same and the electric potential energy is increased by the mass ratio of the oxygen ion to the electron. the electric potential is twice as much and the electric potential energy is increased by the mass ratio of the oxygen ion to the electron.