Neutrons have no repelling electric charge so they're easily captured by the iron group elements.

在核中形成中子中子不带电荷。

Axiom one: all group operations must be closed or restricted to only group elements.

公理一：所有群操作必须是封闭的或仅限于群元素。

Axiom four: every group element has an element called its inverse also in the group.

公理四：每个群元素在群中也有一个元素， 称为它的逆元素。

Even before World War Two, scientists had known about the potential energy inside uranium, the heaviest metal in the periodic table a diagram which groups the chemical elements into rows and columns according to their atomic number and symbol.

甚至在第二次世界大战之前，科学家们就已经知道铀内部的势能。铀是元素周期表中最重的金属，元素周期表是根据原子序数和原子符号将化学元素分成行和列的图表。