Correct Option
The correct option is (a).
Explanation
Elements in the periodic table are classified based on their physical and chemical properties. At room temperature, elements exist in different states of matter (solid, liquid, or gas) depending on their melting and boiling points.
Statement 1 is Correct:
The vast majority of the 118 known elements are solids at room temperature. This includes almost all metals (e.g., Iron, Copper, Gold) and many non-metals (e.g., Carbon, Sulfur, Phosphorus).
Statement 2 is Incorrect:
There are eleven elements that exist in the gaseous state at room temperature (Hydrogen, Nitrogen, Oxygen, Fluorine, Chlorine, Helium, Neon, Argon, Krypton, Xenon, and Radon). The statement likely confuses gases with liquids, as there are only two elements that are liquids at room temperature: Mercury (Hg) and Bromine (Br).
Statement 3 is Incorrect:
Gallium (Ga) and Cesium (Cs) are metals with unusually low melting points of approximately 303 K (30°C) and 302 K (29°C), respectively. Consequently, at temperatures slightly above room temperature (or well above 303 K), they melt and become liquid. They do not remain solid.
Key Takeaway:
Most elements are solids. Only two elements (Mercury and Bromine) are liquids at room temperature, while eleven elements exist as gases. Gallium and Cesium become liquid at temperatures slightly above 303 K.