Mercury is very harmful to the average human being. the mercury can easily be released from the lamp if the lamp is knocked over and broken. mercury is also harmful if inhaled. sodium on the other hand is not harmful in any way.
Answer:
Net Force = 0
Explanation:
Causes objects to accelerate. Balanced Forces. Two equal forces push in opposite direction causing no change in motion causing net force = 0.
Answer:
Do neither of these things ( c )
Explanation:
For length contraction : Is calculated considering the observer moving at a speed that is relative the object at rest applying this formula
L = (l) 
where l = Measured distance from object at rest, L = contracted measured in relation to the observer , v = speed of clock , c = speed of light
you will do neither of these things because before you can make such decisions who have to view the object in this case yourself from a different frame from where you are currently are, if not your length and width will not change hence you can't make such conclusions/decisions .
Intrusive igneous rocks cool down from magma slowly because they form underneath the surface, that will make them have large crystals.
Extrusive igneous rocks cool down from lava rapidly because they form at the surface, so that will make them have small crystals.