Put each event in order of its occurrence, according to the big bang theory. note that more accurate calculations of the age of each event are still actively being researched, so there is some variability in estimations that you might find on the internet. a few seconds after the big bang ~800 million years after the big bang ~9 billion years after the big bang ~1 billion years after the big bang
a. formation of hydrogen and helium atoms
b. formation of large nebulae into protostars and eventually full blown stars
c. early massive stars exploded producing supernovae and heavier elements
d. formation of our sun and the earth

Consider the particle-in-a-box problem in 1d. a particle with mass m is confined to move freely between two hard walls situated at x = 0 and x = l. the potential energy function is given as (a) describe the boundary conditions that must be satisfied by the wavefunctions ψ(x) (such as energy eigenfunctions). (b) solve the schr¨odinger’s equation and by using the boundary conditions of part (a) find all energy eigenfunctions, ψn(x), and the corresponding energies, en. (c) what are the allowed values of the quantum number n above? how did you decide on that? (d) what is the de broglie wavelength for the ground state? (e) sketch a plot of the lowest 3 levels’ wavefunctions (ψn(x) vs x). don’t forget to mark the positions of the walls on the graphs. (f) in a transition between the energy levels above, which transition produces the longest wavelength λ for the emitted photon? what is the corresponding wavele

Which statements describe the movement of ocean currents around the globe? check all that apply. strong winds force warm water to sink to the ocean floor. the coriolis effect causes warm and cold water to mix. cool dense water sinks to the ocean floor. warm water replaces cool surface water. wind blowing parallel to the shore causes upwelling of cool water.

When a light bulb shines, it gives off light energy and energy. a. heat b. potential c. chemical d. electrical