Found ur answer from a simple google search
Answer not by me, by a Reddit user named Exaskryz
There is a 92.4 lb difference here. (39.6 lbs in 3 Magnemite.)
The mass of one electron is 2.00827494 × 10-30 pounds. We need 46,009,636,509,232,147,267,644,538,750,257 electrons to compensate. I am using electrons because, well, it's Magneton and it's electric, and electrons are used to conduct electricity, so it makes sense this way.
Now, to explain why there are 46 nonillion electrons... An electron has an upper bound of 10-22m for a radius (taken from a Penning Trap, but really taken from the Wikipedia page on the electron). Assuming it's a sphere (although physicists would argue it as a point particle that has no volume essentially), this gives a volume of approximately 4.188790204786390984616857844372670512262892532 × 10-66 m3. Multiply this by the number of electrons, and we see these electrons will take up a space (ignoring repulsive forces) of 1.927247147356539373929536086428658875384034605 × 10-34 m3, definitely possible to occur in a Magneton.
So, let's say that it's magnetic strength is strong enough to capture virtual electrons and anti-electrons (1:1 ratio with half of the 1.927247147356539373929536086428658875384034605 × 10-34 composed of each) and prevent them from annihilating each other. But this is only possible with quantum physics.. But, it's viable IMO.
tl;dr Magneton's extra weight is explained by quantum physics.
