Rubidium has 37 elections. there are multiple other sources you could use too confirm this. :-)
I think the correct answer would be B. The process of electroplating uses a direct current in order to give a cheap metal the apperance and resistance of a more expensive metal by coating it with a certain metal. The current reduces the dissolved metal ions to form a thin coating on a surface.
Answer: Aluminium
Explanation: Aluminium metal has a lower density than copper. So, for the same volume of metal used to build a model airplane, the aluminium plane would be very lightweight while that of copper would be heavy. The lightweight airplane will fly easily.
Every moving object has kinetic energy.
Kinetic energy is an energy possessed by an object in motion