Most street lights are made from one of two elements—mercury or sodium. explain why astronomers prefer that cities use sodium street lights instead of mercury street lights.

Astronomers prefer that cities use sodium street lights because the emission spectrum of sodium produces fewer lines than the emission spectrum of mercury -ally

warm front forms when a moist, warm air mass slides up and over a cold air mass. as the warm air mass rises, it condenses into a broad area of clouds. a warm front brings gentle rain or light snow, followed by warmer, milder weather.

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може ли да зареждате повече информация, моля