<span>physical changes
Physical changes happen when something undergoes a transformation that does not alter their total inward arrangement. This appears differently in relation to the idea of compound change in which the creation of a substance changes or at least one substances consolidate or separate to frame a new one</span>
Answer:
From n=1 to n=2
Explanation:
Electrons in n=1 are strongly attracted to the nucleus and therefore will require great force to overcome the electrostatic force of attraction to displace them from the energy level to another.
The electrostatic force reduces as you progress to the outer energy levels.
Answer : The reaction is endothermic.
Explanation :
Formula used :
where,
= change in temperature = 
Q = heat involved in the dissolution of KCl = ?
m = mass = 0.500 + 50.0 = 50.5 g
c = specific heat of resulting solution = 
Now put all the given value in the above formula, we get:
The heat involved in the dissolution of KCl is positive that means as the change in temperature decreases then the reaction is endothermic and as the change in temperature increases then the reaction is exothermic.
Hence, the reaction is endothermic.
To form a salt compound, the acid contribute a NON METAL ION and the base contributes a METAL ION.
In chemistry, acid and base react together to form salt and water only. For the salt formed, the positive metal ion comes from the base while the negative non metal ion comes from the acid.
The correct answer is: [B]:
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" N₂ (g) + 3 H₂ (g) → 2 NH₃ <span>(g) " .
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Note of interest:
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This particular reaction is known as the "</span>Haber process" .
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