Yes, if the angle between the two vectors is more than 90o but less than 2700. (cosΘ is negative)
A negative of a vector represents the direction opposite to the reference direction. It means that the magnitude of two vectors are same but they are opposite in direction.
For example, if A and B are two vectors that have equal magnitude but opposite in direction, then vector A is negative of vector B.
1) That old man is Aksionov.
2) The speaker is asking about the truth of digging an escape hole .
3) The speaker means the prison's wall.
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....

Materials show varying behaviors based on their Poisson's ratio. High Poisson's ratio materials (near 0.5) contract significantly sideways when stretched and expand when compressed, seen in substances like rubber. Low Poisson's ratio materials (near 0) undergo minimal width change during axial deformation, typical of metals and common engineering materials.