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don't know because this is the question which I never heard
Solar energy will not run out (unless the sun burns out), but the supply of fossil fuels we use is slowly depleting. Burning fossil fuel also releases greenhouse gas into the air, which is bad for the atmosphere.
Answer:
The answer is: (a) positive; (b) negative.
Explanation:
The change in enthalpy (ΔH) of a reaction is the amount of energy absorbed or released during a chemical reaction carried out at constant pressure.
a) In an endothermic chemical reaction, heat energy is absorbed by the system from the surrounding. Therefore, the sign of enthalpy change for an endothermic process is positive, ΔH= positive.
b) In an exothermic chemical reaction, heat energy is released by the system into the surrounding. Therefore, the sign of enthalpy change for an exothermic process is negative, ΔH= negative.
Answer:
14.89 g
Explanation:
Please see the step-by-step solution in the picture attached below.
Hope this answer can help you. Have a nice day!
Iron bending is just a physical change because the iron has only changed shape but there is no new substance. Iron rusting is a chemical change because there is a new substance which is rust.
