Spontaneous

• In chemistry, a reaction that occurs naturally without any external energy is called a “spontaneous reaction”.
• When we want to express something similar in Japanese, we don’t have a perfect word for it, so we use the term “spontaneous”.
  • “自発的” (jihatsuteki) is a bit different because it implies that the energy is coming from within oneself.
  • “自然に” (shizen ni) also doesn’t quite capture the exact meaning.