Answer: The black ball will have more mass than the white ball.
Explanation: Density of a substance is defined as the ratio of mass and volume occupied by the substance.
Mathematically,

We are given that the two balls are of same size, which means that the volume of both the balls are same. We are also given that the black ball is more dense than the white ball, which means that the black ball will have more mass.
As, 
Answer:
FALSE
nuetrons do indeed have no charge, however they are nearly 2000 more times massive than electrons.
Answer : The correct option is, (B) 273.15 K and 1 atm
Explanation :
STP : STP stands for standard temperature and pressure.
STP conditions :
The temperature is,
or
or 
The pressure is,
or 
The volume is 22.4 L for 1 mole of a substance.
Hence, the correct option is, (B) 273.15 K and 1 atm