The glow of a neon light is caused by electrons emitting energy as they a. move from lower to higher energy levels b. collide with the nucleus c. move from higher to lower energy levels d. collide with other electrons

The answer is c

because the atoms of inert gases such as helium, neon or argon never form stable molecules by chemically bonding with other atoms. One need apply only a modest electric voltage to electrodes at the ends of a glass tube containing the inert gas and the light begins to glow.

F  you double the  force, you double the acceleration, but  if  you double the  mass, you velocity. all bodies accelerate at the  same  rate regardless of size or  mass.

The figure is missing but we can answer anyway.the correct answer is "releasing the string". in fact, when the person is holding the bow and the arrow, the kinetic energy of the arrow is still zero (because the arrow is not moving). the moment the arrow is released, it acquires a velocity v, so its kinetic energy will become different from zero: where m is the mass of the arrow and v its velocity.  all the other options, instead, do not increase the kinetic energy of the system: -  pulling farther back on the string : this will just increase the elastic potential energy of the system-  holding the arrow higher: this will increase the gravitational potential energy of the system (which is given by u=mgh, where h is the height above the ground)-  decreasing the mass of the arrow: this will decrease the gravitational potential energy of the system (which is given by u=mgh, where m is the mass)