a)When silver nitrate comes in contact with skin, it is reduced to white color metallic silver.In most cases, a black stain appears due to formation of finely divided silver which has black color.

The black color is due to the decomposition of the Ag+ ion into Ag, silver. Silver nitrate will slowly decompose with the silver ion reverting to elemental silver. The microscopic particles of silver are so small that they absorb light instead of reflecting it, and so appear black, instead of silver....

There is, for sure, effect of gravity on fire. We know for a fact that fires on Earth are "pointy" while those in zero-gravity are "round". This is because fire is simply glowing gas. Gas is matter and matter has weight. For a body to have weight, gravity must influence it in some way. 

It is theoretically possible for a substance to have a negative value of cubical expansivity, which means that the substance would contract rather than expand when the temperature increases. However, it is very rare for a substance to have a negative value of cubical expansivity over a significant range of temperatures.

One example of a substance that has a negative value of cubical expansivity over a limited range of temperatures is water. Water has a positive value of cubical expansivity at...

If vectors are arranged as trigonal planar and have equal magnitude, it is an ideal case of zero resultant.

1. Statement; true
2. Statement; false
3. Statement; true
4. Interrogative sentence; not a statement
5. Imperative sentence; not a statement
6. Exclamatory sentence; not a statement