alkali ion

例句：

1. 1. The solution is alkaline, so it can react with acids.
   这个溶液是碱性的，所以它可以与酸反应。
2. 2. Alkali metals are elements that have a high boiling point and can be used to make batteries.
   碱金属是那些具有高沸点的元素，可以用于制造电池。
3. 3. The alkaline earth metals are similar to the alkali metals but have lower melting points.
   碱土金属与碱金属相似，但熔点较低。