Not for sale at Arbee's this alkali is a real go-getter in vacuum tubes and is known for its ruby-colored flame test?

What is cesium? Cesium is a highly reactive alkali metal that is not typically found for sale at Arbee's. It is commonly used in vacuum tubes due to its ability to efficiently emit electrons. When cesium is burned, it produces a distinctive ruby-colored flame, making it easily identifiable in a flame test.