Aquantum system has three energy levels, so three wavelengths appear in its emission spectrum. the shortest observed wavelength is 218 nm ; light with a 454 nm wavelength is also observed. what is the third wavelength?

I'm kinda lost ! 1. when marilyn takes her pet dog for a walk, the dog walks at a veryconsistent pace of 0.55 m/s. draw a position-time graph to representmarilyn's dog walking the 19.8 m distance from the front of her house tothe nearest fire hydrant.2. both car a and car bleave school when a stopwatch reads zero. car atravels at a constant 75 km/h, and car b travels at a constant 85 km/h.a) draw a position-time graph showing the motion of both cars. howfar are the two cars from school when the stopwatch reads 2 hrs? calculate the distances and show them on your graph.b) both cars passed a gas station 120 km from the school. when dideach car pass the gas station? calculate the times and show themon your graph.3. the figure below shows the position-time graph showing a shopper'smovement up and down the aisle at a store.a) write a story describing the shopper's movements at the store.b) when does the shopper have a position of 6 m? c) how much time passes between when the shopper enters the aisleand when he gets to a position of 12 m? what is the shopper's averagevelocity between 37 s and 46 s?

1) what is the power in horsepower of a 100 watt light bulb? what is the power in kilowatts of a 200 horsepower engine? 2) if a cars engine is providing 3000 n of force to keep the car moving at 5 m/s, what is the engine’s effective power? 3) how many gallons of water will be pumped from a well 30 feet deep by a 1/2 hp engine in 1 minute? (1 gallon weighs 8.34 pounds)

How do you know how many valence electrons an atom has?