Caco3 is an example of which type of material

Suppose you mix one mole of sulfuric acid (h2so4) with 1 mole of sodium hydroxide(naoh). why does the ph of the solution remain below 7? ( explain so i can get better understanding! )

When did stem cell research become known ? who discovered stem cell? what experiments or studies have been conducted so far?

The chemical formula for emerald is be3al2(sio3)6.an emerald can be decided as