Originally Posted by SageHunter
A HDD is not in any way a closed system so the law of conversion of mass is not at all relevant.
No such thing as a "more charged" electron. The electron itself is the charge (bit simplified, but for this argument it holds true). While electrons can have different states of energy, they are always charged with -1. So an SSD would have extra electrons.
Also, E=MC², as you mentioned later on, states that energy have mass. Though this is an oversimplified version of the truth. Photons have mass, so light has mass. Heat is just molecules moving.
Wikipedia is probably the most accurate information source out there. Sure, anyone can change it, but that doesn't make it inaccurate. If you change an article, exactly what you changed and the stated reason why is easily accesible, so filtrating away inaccurate information is simple. Most people editing articles on physics (read: all people) only do so when they know they are correct. Sources are allways given, so if you have any doubts regarding the subject, just check it's sources. If someone made a bad or incorrect edit, every single previous edit of the page is available for reading.
Wikipedia is also better than most other media, such as physics books becouse it is constantly updated, gives sources and directs you to relevant related information.
The question at hand has already been answered so I won't bother with an input, but I will thank all the answers; I learned something new.