Answer:

Explanation:
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In this case, since the standard enthalpy change for a chemical reaction is stood for the enthalpy of reaction, for the given reaction:

We set up the enthalpy of reaction considering the enthalpy of formation of each species in the reaction at the specified phase and the stoichiometric coefficient:

In such a way, by using the NIST database, we find that:

Thus, we plug in the enthalpies of formation to obtain:

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Answer:
This is a single replacement reaction because I replaces Br.
transverse wave
A transverse wave is a wave in which particles of the medium move in a direction perpendicular to the direction that the wave moves.
I believe the most appropriate answer would be to change the core from wood to iron. This is because iron is a magnetic material while wood is not magnetic hence cant acquire magnetism. Other factors that would increase the strength of electromagnet would be; increasing the amount of electric current, and increasing the number of windings.