Which of the processes is exothermic? evaporation of alcohol sublimation of iodine solidification of volcanic lava burning of paper

The electric field direction is defined by the direction of the force felt by (select one of the following answers): 1. a negative charge. 2. a positive charge. 3. both positive and negative charges.

Determine the net charge of the predominant form of arg at (a) ph 1.0, (b) ph 5.0, (c) ph 10.5, and (d) ph 13.5

Why does the equilibrium position of the spring change when a mass is added to the spring? will the mass oscillate around the new equilibrium position of the spring or the previous position without a mass attached to the spring? if the equilibrium position of the spring changes by 20 cm (assuming no initial mass) when a mass is added to the spring with constant 4.9 kg/s^2, what is the mass of the object attached to the spring?