What is a wave that bounces back from a barrier called?

Which of the following is a homogenous mixture? o a. a toy box filled with toys o b. blood o c. trail mix o d. spaghetti and meatballs submit

How is sound energy produced a. vibrating objects b. objects being heated c. temperature differences d. stationary objects

(a) calculate the number of electrons in a small, electrically neutral silver pin that has a mass of 10.0 g. silver has 47 electrons per atom, and its molar mass is 107.87 g/mol. (b) imagine adding electrons to the pin until the negative charge has the very large value 1.00 mc. how many electrons are added for every 109 electrons already present