sally was trying to create a model the represents the composition of the galaxy. In her model, she needs to distinguish galaxies from other systems of celestial objects. which of the following best describes the composition of a galaxy?

Does anyone know how to solve this problem? i really need . i made an attempt but i just cant get it. a metal rod is 25.000 cm long at 25.0 degrees celsius. when heated to 102.0 degrees celsius, it is 25.054 cm long. what is the coefficient of linear expansion for this metal.

If the chemical properties of a substance remain unchanged and appearance or shape of a substance changes it is called a ?

Avoltaic cell converts chemical energy to