A luminous object and a screen are placed on an optimal bench and a converging lens is place between them to throw a sharp image of the object on the screen. The linear magnification or
image is found to be 2.5. The lens is now moved 30 cm. nearer the screen and a sharp image again
formed. Calculate the focal length of the lens.

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Consider three unlabeled bottles, each contain small pieces of one of the following metals. - magnesium - sodium - silver the following reagents are used for identifying the metals. - pure water - a solution of 1.0 molar hcl - a solution of concentrated hno3 (a) which metal can be easily identified because it is much softer than the other two? describe a chemical test that distinguishes this metal from the other two, using only one of the reagents above. write a balanced chemical equation for the reaction that occurs. (b) one of the other two metals reacts readily with the hcl solution. identify the metal and write the balanced chemical equation for the reaction that occurs when this metal is added to the hcl solution. use the table of standard reduction potentials (attached) to account for the fact that this metal reacts with hcl while the other does not. (c) the one remaining metal reacts with the concentrated hno3 solution. write a balanced chemical equation for the reaction that occurs. (d) the solution obtained in (c) is diluted and a few drops of 1 m hcl is added. describe what would be observed. write a balanced chemical equation for the reaction that occurs.

Electrons are extremely important to what area of technology? a) anti-aging research b) household product development c) electronics d) drug discovery

Why doesn't heat added to water make the tempature rise above 100c