Answer:
Light
Explanation:
The discovery of light from the other side of a black hole was predicted by Einstein's theory of general relativity. ... The research began with a slightly different aim of a more common light formed by a black hole: the corona which wraps around the outside of it, formed as material falls in.
Answer:

Explanation:
Alkaline earth metals are in group 2. The number of valence electrons of elements in group 2 is 2.
Answer:
look at the photo........................
How likely and forcefully a substance reacts with oxygen, water, acids and other salts