one of the more fun aspects of learning kanji is learning one and then discovering the vocabulary combinations you can make out of what you know. it's a great puzzle!
like, from 気 (energy) you can make…
popular: 人気 (person energy)
serious: 本気 (book energy)
weather: 天気 (heaven energy)
calm: 平気 (flat energy)
feeling: 気分 (energy part)
