1A molecule: the smallest unit of a chemical substance, formed by two or more atoms bonded together, which determines the substance's properties.
水は酸素原子と水素原子が結合した分子だ。
Water is a molecule made of oxygen and hydrogen atoms bonded together.
この反応では大きな有機分子が生成される。
A large organic molecule is produced in this reaction.
分子の構造を調べるためにスペクトル解析を行った。
We performed spectral analysis to examine the molecular structure.
2The numerator of a fraction — the number written above the line, indicating how many parts of the whole are being taken.
分数3/4では、3が分子で4が分母だ。
In the fraction 3/4, 3 is the numerator and 4 is the denominator.
通分するときは、分子と分母に同じ数を掛ける。
When finding a common denominator, multiply the numerator and denominator by the same number.
3An element or member of a group — a person or factor forming part of it, especially one with a distinctive trait (e.g. "radical elements").
警察は過激な分子の取り締まりを強化した。
The police strengthened their crackdown on radical elements.
その政党には改革を求める分子が少なくない。
There are quite a few members within the party who demand reform.
4A small particle or microparticle (used in words like "微分子", microparticle).
空気中に浮遊する微小な分子が計測装置で検出された。
The tiny particles floating in the air were detected by the measuring device.
このフィルターは分子レベルの微粒子まで除去する。
This filter removes even particles at the molecular level.