If a carbon atom can form four covalent bonds, it also has four valence electrons. For neutral atoms, the number of valence electrons the same as an atom's main group number.
Balanced chemical reaction:
PbO₂<span>(s) + Sn(s)+ 4H</span>⁺(aq) → Pb²⁺(aq) + Sn²⁺(aq) + 2H₂O<span>(l).
Oxidation half-reaction: Sn </span>→ Sn²⁺ + 2e⁻.<span>
Reduction half-reaction: PbO</span>₂ + 4H⁺ + 2e⁻ → Pb²⁺ + 2H₂O.
Net reaction: Sn + PbO₂ + 4H⁺ + 2e⁻ → Sn²⁺ + 2e⁻ + Pb²⁺ + 2H₂O.
Oxidation is increase of oxidation number, reduction is decrease of oxidation number.
Answer:
The answer is the same as .
Explanation:
There are 3 atoms in NaOH, 1 sodium, 1 oxygen and 1 hydrogen.
There are 3 atoms in H2O, 2 hydrogen and 1 oxygen.
<span>So, when you make something boiling or melting, its still the same substance. Water doesn't change into something else, just change its state of matter. When you burn something, one substance reacts with another. For example, when you burn carbon in oxygen, you get carbon dioxide. That's the difference.</span>
