Answer:
1st one is...
Explanation:
The 1st one is change in size or shape. 2nd one is formation of precipitate. 3rd one is physical change. 4th one is formation of gas.
Water is an incomplete combustion as water is still produced by carbon monoxide and carbon are produced instead of carbon dioxide.
Answer:
D.) Mg(NO₃)₂
Explanation:
Since magnesium (Mg) is a metal and nitrate (NO₃) is a polyatomic anion, they would combine to form an ionic compound. Magnesium would form the cation Mg²⁺ because it generally has 2 valence electrons. Nitrate always has a -1 charge.
In order for the overall compound to be neutral (have a charge of 0), there must be one Mg²⁺ and two NO₃⁻ ions in the compound (+2 + (-1) + (-1) = 0).
Therefore, the formula for the compound formed is Mg(NO₃)₂.