Answer:
Na₂SO₄
Explanation:
Barium nitrate, Ba(NO₃)₂ produce precipitate with SO₄²⁻, CO₃²⁻. That means the precipitate could be obtained from Na₂SO₄ and Na₂CO₃.
Also, magnesium nitrate, Mg(NO₃)₂, produce precipitate just with CO₃²⁻. As the unknown solution produce no precipitate, the unknown compound is:
<em>Na₂SO₄</em>
<span>B)Na2SO4 and SrSO4 is the answer</span>
I don’t know what the “cheater” way is, however you can easily judge how many valence electrons an element has by looking at its group number on the periodic table.
Bonding in chemistry is completely and totally due to electrons. Every element wants 8 electrons in its outer shell in order to be stable. This is what we call the “Octet Rule”.
The two most abundant elements in the universe are HYDROGEN AND HELIUM. Hydrogen is the most abundant element followed by helium.
Hydrogen is the lightest of all element and the first element to be formed, followed by helium which has just two atoms.
