I believe the answer is C because the first two are mechanical hazards and C mentions plug which is electrical.
Answer:
Momentum of first train car will reduce
Explanation:
When the moving care collides with the stationary car, it will increase the momentum of the stationary car. However, its own momentum will reduce.
It is so because the speed of the first train car will reduce after collision due to loss of energy in the collision while the stationary car may gain some momentum due to rise in velocity from zero (velocity at stationary position).
The answer is true. One neutral atom of carbon has four valence electrons.
An easy way of finding out is to check out the periodic table and look at which main number group the element is in. Carbon is in group number four, which would mean it has four valence electrons.
Hope I was able to help!
