When scientists make a model to study a system, such as a coral reef or the human body, which of these should they be sure to include? a include only inputs b include no set boundaries c include a limited number of parts d include both biotic and abiotic influences Pls hurry

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?

What is the most common form of matter in the universe

How much energy is required to vaporize 2 kg of copper? a 4730 kj b 207kj c 9460 kj d 414kj