Two independent variables could change at the same time, and you would not know which variable affected the dependent variable
Answer:
Solution
Explanation:
Compound - a chemical substance made by elements of different densities to form a chemical union.
Element - Any one of the simple chemical substances that can't decompose in a chemical reaction
All i know is that #7 is true
Answer:
A. The increase in the mass of the magnesium oxide was due to oxygen atoms in the air.
Explanation:
Burning occurs in the presence of oxygen. A chemical combination occurs between Mg and O in that the atom of magnesium attracts one another.
Mg + O₂ → MgO
Starting with the magnesium, on reacting with oxygen a new compound forms. This is why there is mass increase in the MgO compared to the starting material.
