The object has an overall positive charge.
Answer:
1. B, D,
2.A, F
Explanation:
1. According to the law of conservation of mass, In a course of chemical reaction, matter can neither be created nor destroyed but can be changed from one form to another. This means the amount of matter at the begining and ending of a reaction must be thesame.
2. Chemical reaction is not easily reversible. when gas is produced, provided the reaction system is an open system, the gas cannot be recovered and the reactants cannot be recovered from the products. likewise color change are attributed to chemical reaction
Explanation:
At each reflecting surface (benzene and glass) there will be 180 degree phase change.
Now, for constructive interference the optical path in benzene is
.
Formula to calculate thickness of a benzene thin film is as follows.
Optical path length through benzene (
) = 
Hence, substituting the given values into the above formula as follows.
Optical path length through benzene = 
d = 
=
=
(as 1 nm = 
= 204.9 m
Thus, we can conclude that minimum thickness of benzene is 204.9 m.