Lighter elements are a type of element in Powder Game and Powder Game 2. Lighter elements ignite flammable and combustible elements. However, some flammable/combustible elements are not affected by some of these elements - for example, superball will not burn on contact with fire or thunder. All lighter elements show up in BG-dark, and their heat shows up in BG-TG.
There are currently six lighter elements in Powder Game and Powder Game 2:
Thunder-charged metal and -glass in Powder Game 2 do not exhibit the lighter element qualities it does in the original Powder Game. For example, they produce "light" in BG-dark and "heat" in BG-TG in Powder Game 1, but they do not in Powder Game 2. They are also non-lethal to players and fighters in Powder Game 2. It is notable that the lighter element characteristics both thunder-charged metal and -glass have are actually caused by the thunder in them, thus disqualifying them as lighter elements.
Bomb appears to be a lighter element as it explodes nitro, but it is only true for nitro, because the nitro particle which was touched by the bomb is moving at a high velocity away from the impact point. The high velocity detonates the particle, which causes all of the nitro particles in its area to explode.