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. 18 - noble gases
2. 17 - halogens
3. 2 - alkaline earth metals
4. 1 - alkali metals
The element described in the question, with seven electrons in its outer shell, being toxic, a gas at room temperature, and highly reactive, belongs to group 17 of the periodic table, which is the halogens. Therefore, the correct answer is option 2 - 17: halogens.
Based on the given information, the element that the scientist is studying belongs to Group 17 of the periodic table, which is the halogens.
To determine the group in which the element belongs, we need to consider its characteristics mentioned in the question.
- The element has seven electrons in its outer shell: This indicates that the element is in Group 17 (also known as the halogens) because Group 17 elements typically have seven valence electrons.
- The element is fairly toxic: While toxicity varies among elements, many halogens, such as chlorine and fluorine, are toxic.
- The element is a gas at room temperature: Among the elements in Group 17, fluorine (F2) and chlorine (Cl2) are gases at room temperature, while bromine (Br2) is a liquid, and iodine (I2) is a solid.
- The element is highly reactive: Halogens are known for their high reactivity, and they readily form compounds with other elements.
Considering all these characteristics, the element belongs to Group 17 of the periodic table, which is the halogens. Therefore, the correct answer to the question is option 2 - 17: halogens.