Answer:
Flint glass is combination of silicon dioxide (SiO2) with lead or potassium. It creates a relatively high refractive index and high degree of light dispersing power compared to other types of glass.
Explanation:
:)
A negative ion is a atom that has an extra electron, but the same # of protons
Answer:

Explanation:
At some distance from the Earth the force of attraction due to moon is balanced by the force due to Moon
so we will have

now we have


so we will have

Now by energy conservation


