What causes the bright lines in the emission spectrum of an element to occur?

One complete revolution of Earth around the sun takes about a. one rotation. b. one season. c. one year. d. one eclipse.

Hi partial sum addition I have a problem 245 + 92 is 200 + 90 or do I do 200 + 100

How many amps does a 60 watt light bulb use when it's powered by 120 volts

Which statement is part of Dalton's atomic theory? A. Atoms are composed of protons, neutrons, and electrons. B. Elements can have atoms that are isotopes. C. One type of atom cannot be changed to another type by a chemical reaction. D.

Compare semiconductors with both metals and nonmetallic in terms of their ability to conduct electricity, and state where semi conductors are located on the periodic table

A package of aluminum foil is 59.3 yd long, 13 in. wide, and 0.00040 in. thick. If aluminum has a density of 2.70 g/cm3, what is the mass, in grams, of the foil?

A teacher pushed a 10-kg desk across a floor for a distance of 5 m she exerted a horizontal force of 20 N how much work is done

Carbon and oxygen, both nonmetals, bond to form a compound. What is the name of the carbon compound with one carbon and two oxygens? A) carbon oxide B) carbon dioxide C) carbon dioxygen D) monocarbon dioxide

Salt water has greater density than fresh water. A boat floats in both fresh water and in salt 12) water. Where is the buoyant force greater on the boat?

A 1000-kg space probe is motionless in space. to start moving, its main engine is fired for 5 s during which time it ejects exhaust gases at 5000 m/s. at the end of this process it is moving at 20 m/s. the approximate mass of the ejected gas is: