En un libro de astronomía, Elena encuentra el siguiente espectro cósmico de una ga- laxia, tomada en dos momentos diferentes: Las diferencias que se observan en el espectro de la galaxia constituyen una evidencia:

I. de que la galaxia se está alejando.
II. de que el universo se encuentra en expansión.
III. del origen del sistema solar.

¿Cuál o cuáles de las siguientes afirmaciones es o son correctas?

A
Solo I.

B
Solo II.

C
I y II.

D
II y III.

E
I, II, III.

Electroplating is a way to coat a complex metal object with a very thin (and hence inexpensive) layer of a precious metal, such as silver or gold. in essence the metal object is made the cathode of an electrolytic cell in which the precious metal cations are dissolved in aqueous solution. suppose a current of 480.ma is passed through an electroplating cell with an aqueous solution of agno3 in the cathode compartment for 46.0 seconds. calculate the mass of pure silver deposited on a metal object made into the cathode of the cell. round your answer to 3 significant digits. also, be sure your answer contains a unit symbol. ×10μ

When you turn on a battery-operated device, an electrical circuit is

When is a current produced? when the terminals of an electrochemical cell are connected by a wire if the electric circuit is opened in an electrochemical cell if the electrolyte is removed from an electrochemical cell when the electrodes are reversed in an electrochemical cell