B2 the smallest unit of any chemical element, consisting of a positive nucleus surrounded by negative electrons. Atoms can combine to form a molecule原子
More examples
The nucleus of a deuterium atom contains a proton and a neutron.
Scientists are working to harness the power of the atom.
👨🏻🏫 Mr. Ng 劍橋詞典 📚 – cambridge.mister5️⃣.net
切換為繁體中文