一、根据元素在周期表中的位置1.同周期从左到右,非金属性逐渐增强,金属性逐渐减弱。2.同主族从上到下,非金属性逐渐减弱,金属性逐渐增强。二、根据原子结构原子半径(电子层数)越大,最外层电子数越少,金属性就越强,反之则越弱;原子半径越小,最外层电子数越多,非金属性越强,反之则越弱。三、根据实验 First, according to the elements in the periodic table position 1. With the same period from left to right, non-metallic gradually increased, the metal gradually weakened. 2. With the main group from top to bottom, non-metallic gradually weakened, gradually increased metal. Second, according to the atomic structure of the atomic radius (electron layer) is larger, the outermost electron number is less, the stronger the metal, the weaker the contrary; the smaller the atomic radius, the outermost electron number, non-metallic The stronger, the weaker the contrary. Third, according to the experiment