When a balloon is rubbed with human hair, the balloon acquires an excess static charge. this implies that some materials

a)
conduct electricity, while others do not.
eliminate

b)
can accept protons more easily than others.

c)
can give up electrons more readily than others.

d)
repel negative objects, and others attract them.

*drag each tile to the correct location in the sequence* the table shows chronological events in the life of our sun, a medium-sized star. place the missing events into the correct rows of the table.

Some material consisting of a collection of microscopic objects is kept at a high temperature. a photon detector capable of detecting photon energies from infrared through ultraviolet observes photons emitted with energies of 0.3 ev, 0.5 ev, 0.8 ev, 2.0ev, 2.5ev, and 2.8ev. these are the only photon energies observed. (a) draw and label a possible energy-level diagram for one of the microscopic objects, which has four bound states. on the diagram, indicate the transitions corresponding to the emitted photons. explain briefly. (b) would a spring–mass model be a good model for these microscopic objects? why or why not? (c) the material is now cooled down to a very low temperature, and the photon detector stops detecting photon emissions. next, a beam of light with a continuous range of energies from infrared through ultraviolet shines on the material, and the photon detector observes the beam of light after it passes through the material. what photon energies in this beam of light are observed to be significantly reduced in intensity (“dark absorption lines”)? explain briefly.

What is the force that opposes motion and works against the downward pull? a) friction b) gravity c) weight d) acceleration