Answer:
Endothermic.
Explanation:
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In this case, it is necessary to keep in mind that exothermic processes are characterized by the release of energy and the endothermic processes by the absorption of heat. In such a way, every process from solid to liquid or gas is endothermic as they require energy to separate the molecules and therefore turn out in the phase change. On the other hand, every process from gas to liquid or solid is exothermic as heat is released to rejoin the molecules and produce the phase change.
Therefore, since solid water molecules tend to be well-arranged, it is necessary to add heat to the system to produce the phase change until gas; in such a way, this process is endothermic as energy must be absorbed by the ice.
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Answer:
11
Explanation:
The atomic number = number of protons. The mass number (23) = sum of number of neutrons and protons. Since you know the mass number is 23 and it has 12 neutrons, 23-12 gives you 11 protons, so its atomic number is 11.
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