Question

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

Explanation:

• Alkali metals (Group 1) have 1 valence electron.
• Alkaline earth metals (Group 2) have 2 valence electrons.
• Noble gases (Group 18) have 8 valence electrons (except helium with 2).
• Halogens (Group 17) have 7 valence electrons. They are often toxic gases at room temperature and highly reactive.

Answer:

17 - halogens