Is the something missing from the question
Answer:
The octet rule is a chemical rule of thumb that reflects the observation that main group elements tend to bond in such a way that each atom has eight electrons in its valence shell, giving it the same electronic configuration as a noble gas
Explanation:
Electrons fill the electron orbitals (s, p, d, or f) starting from the lowest energy level going to the highest energy level.
I hope this helps. let me know if you need more information such as what the
Heat needed=mcθ
=7×0.031×(42-17)
=5.425cal
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.