What questions in particle physics led to the necessity for the development of the quark theory? what were the deficiencies in the older theories that made it necessary to formulate a theory of particle structure on a level below (i. e., smaller than) that of electrons, protons, and neutrons? what observational evidence is there for the existence of smaller particles within the proton, for example?

the answer is false. this is because for ice to melt, it requires latent heat of melting. latent heat means heat energy required to change phase without any increase in temperatures. therefore, the ice will take energy from the environment to melt hence atmospheric temperatures will reduce.

the answer is the first electromagnet (a). this is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. this enables more atoms in the metal to become aligned hence becoming more magnetized.