Explain why melting ice is considered an endothermic reaction, science homework help

  1. 1. Explain why melting ice is considered an endothermic reaction. 2. In what sense are oxidation and reduction reactions opposites? 3. When is an electon a valence electron? Why are valence electrons important in chemical reactions? 4. What is an alloy? 5. What is polymerization? Give an example.