Black hole, or a singularity contained within an event horizon through which no light can escape.
Any substance changes to another substance that means the change of the physical property. Like water () has different state which changes as the temperature changes. It remain as liquid in the room temperature, in solid form at or below 0°C and vapor phase on or above 100°C. But in all the stage or phase of the substance the composition of the water i.e. remains. Thus the chemical property remains fixed when a substance change to other substance.
Answer:
C. It is reactive because it must gain two electrons to have a full outermost energy level.
Step-by-step explanation:
The electron configuration of this element ends in 2s²2p⁴.
A filled energy level would end in 2s²2p⁶.
The element will be reactive, because it must gain electrons to have a full energy level, and it needs two more electrons to do this.
Answer: Molarity of 
anions in the chemist's solution is 0.0104 M
Explanation:
Molarity : It is defined as the number of moles of solute present per liter of the solution.
Formula used :
where,
n= moles of solute
= volume of solution in ml = 100 ml
Now put all the given values in the formula of molarity, we get
Therefore, the molarity of solution will be 
As 1 mole of 
gives 2 moles of
Thus 
moles of gives =
Thus the molarity of anions in the chemist's solution is 0.0104 M
Density is a physical property. It's measured and doesn't change the object chemically.
