John and Jake are working in a lab and see 2 stars in the sky that they are interested in knowing more about. John and Jake would like to know what
elements make up these stars. What tool would best help them?

How many moles are in 43.9 l of oxygen

The atoms of a solid aluminum can are close together, vibrating in a rigid structure. if the can is warmed up on a hot plate, what happens to the atoms?

Consider hydrogen in an excited state n = 5n=5 that emits photons to reach the ground state. there are various possible transitions other than straight to the ground state that can occur; for example, it can drop to the n = 3n=3 state followed by the n = 3n=3 to the ground state transition. which of the possible transitions will result in the emission of a photon in the visible region?