Aquantum dot is modeled as a particle (exciton) of reduced mass equal to the mass of the electron confined in a cubic 3-d box of dimension l40nm on a side: (a) sketch the first four sharp energies i. e., draw an energy level diagram. label each energy with the appropriate quantum number triplet, nz; ny; n. how many different solutions to the time-independent schrödinger equation exist at each energy? (b) the confinement energy is 1.9 mev. what are the quantum numbers nai ny; n? are they uniquely determined? (c) quantum dots can be synthesised in a range of sizes, by changing the reaction conditions. if the reaction temperature is increased so that the quantum dots produced are 10% smaller in all three dimensions, how will this impact on the energy spectrum from part (a)? (d) write down a possible wavefunction for the confined particle. what is the probability density for finding the particle at position (x; y, z) = (0: 67l; 0: 67l: 0: 67l)?

The graph describes the motion of an object. the object moves with from a to b. it from b to c. it moves with from c to d.

When temperature of a substance increases, of its particles increase resulting in more between particles. real world applications of thermal expansion absolute zero (-273 degrees c) is the lowest possible temperature on the kelvin scale. it is a measure of where a substance has no kinetic energy. heat is a process of the . energy flows spontaneously from a object to a until equilibrium is reached. heat is measured in heat is transferred throughis a method of heat transfer that occurs between particles of matter that are in direct contact with each other. are poor conductors that impede / reduce the rate of heat transfer. is a method of heat transfer that occurs in fluids (non-solids) by means of currents. real world application of convectiona method of heat transfer through electromagnetic waves. when energy moves from one object to another inside a closed system, no energy is or in the system in the transaction. systems will spontaneously move to a state of organized energy or high disorder over time called

Two carts, one of mass 2m and one of mass m, approach each other with the same speed, v. when the carts collide, they hook together. assume that positive momentum is to the right. which graph best represents the momentum of both carts over time, before and after the collision?