The correct option is A is true but R is false
Explanation
Elements are broadly classified into metals and non-metals based on their physical and chemical characteristics. While physical states (solid, liquid, gas) vary across the periodic table, specific exceptions exist regarding the standard states of elements at room temperature.
Statement-wise Analysis
- Assertion (A): Correct. Bromine (Br) is a chemical element in the halogen group (Group 17). It is a non-metal and is distinctively known for being a reddish-brown liquid at room temperature.
- Reason (R): Incorrect. Non-metals exist in all three states of matter at room temperature. While many are gases (e.g., Oxygen, Nitrogen, Chlorine) and some are solids (e.g., Carbon, Sulfur, Iodine), the statement that all non-metals are only solids or gases is false because Bromine exists as a liquid.
Key Takeaway: Bromine is the only non-metal that is liquid at room temperature, just as Mercury is the only metal that is liquid at room temperature.