Physical Change because a new substance was not created and if it was a chemical change, a new substance would have to be created.
Answer:
Polythene has the lowest melting/boiling point from all the other covalent structures mentioned in this question.
Explanation:
Ionic bonds are bonds formed as a result of the electrostatic attraction between two species.
- This bond type is an interatomic bond.
- It forms when two specie with a large electronegative difference between them combines.
- This is usually a metal and a non-metal.
- The metal loses its valence electrons and becomes positively charged.
- The non-metal gains the electron and becomes negatively charged.
- An electrostatic attraction between the two specie leads to the formation of an ionic bond.
- They are solids with a high melting point.
- They are soluble in polar solvents.
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Answer:4 and 3
Explanation:just took the test
The energy produced by burning : -32.92 kJ
<h3>Further explanation</h3>
Delta H reaction (ΔH) is the amount of heat change between the system and its environment
(ΔH) can be positive (endothermic = requires heat) or negative (exothermic = releasing heat)
The enthalpy and heat(energy) can be formulated :

The enthalpy of combustion of naphthalene (MW = 128.17 g/mol) is -5139.6 kJ/mol.
The energy released for 0.8210 g of naphthalene :
