Potential energy is stored energy
For your first question, that equation only works if your situation is occurring at a constant temperature. Your original question is such a situation - everything occurs at 298.15 K. Therefore, you can use this value in the equation to calculate work.
For your second question, Charles' Law describes how the volume of gas changes as you heat or cool it, PROVIDED PRESSURE AND MOLES OF GAS REMAIN CONSTANT THE WHOLE TIME. In your original question above, temperature stays constant while volume changes. However, what they don't tell you is that this necessarily requires a change in either pressure or moles of gas. Because the question works with the same sample the of gas the whole time (i.e. moles are constant), it is pressure that is changing (and this change will occur according to Boyle's Law, since temperature and moles are held constant).
Hope that clarifies things!
Answer: Metals bond with metals.
Explanation: A metallic bond is a sharing of electrons between many atoms of a metal element. Metallic bonding is when positive ions (metals) are in a 'sea of negative electrons'. The electrons are delocalised, which means they can move around easily and carry charge, and this enables it to conduct electricity, even in a solid state. The big pool of electrons is like a free-for-all in that any valence electron can move to any atom within the material.
The last electron on the outer most shell. or d oder of dere atomic no