A scientist studies an element that has seven electrons in its outer shell, is fairly toxic, is a gas at room temperature, and is highly reactive. To which group of the periodic table does this element belong? (1 point)

Question

• 1 - alkali metals
• 2 - alkaline earth metals
• 18 - noble gases
• 17 - halogens

Answer 1

The element described belongs to group 17, which are the halogens. Halogens have seven electrons in their outer shell, are highly reactive, can be toxic, and include gases at room temperature such as chlorine and fluorine.