전이후 금속(post-transition metal, 轉移後金屬)
주기율표의 p-구역에 있는 금속 원소를 말한다. 전이 금속과 준금속 사이에 자리하고 있으며, 전기음성도가 알칼리 금속이나 알칼리 토금속, 전이 금속보다 크다. 전이 금속에 비해 녹는 점과 끓는 점이 낮고, 무르다.
전이후 금속에 속하는 원소는 다음과 같으며, 점선으로 표시한 원소들을 포함시키기도 한다. 여기 실린 7주기 원소들의 경우 아직 화학적 성질이 밝혀지지 않았으나, 전이후 금속의 성질과 비슷한 성질을 보일 것으로 예측된다.
post-transition metal
The metallic elements in the periodic table located between the transition metals to their left and the chemically weak nonmetallic metalloids to their right have received many names in the literature, such as post-transition metals, poor metals, other metals, p-block metals and chemically weak metals. The most common name, post-transition metals, is generally used in this article.
Physically, these metals are soft (or brittle), have poor mechanical strength, and usually have melting points lower than those of the transition metals. Being close to the metal-nonmetal border, their crystalline structures tend to show covalent or directional bonding effects, having generally greater complexity or fewer nearest neighbours than other metallic elements.
Chemically, they are characterised—to varying degrees—by covalent bonding tendencies, acid-base amphoterism and the formation of anionic species such as aluminates, stannates, and bismuthates (in the case of aluminium, tin, and bismuth, respectively). They can also form Zintl phases (half-metallic compounds formed between highly electropositive metals and moderately electronegative metals or metalloids)