Did you know that the Periodic Table of Elements was first created in the 19th century by Dmitri Mendeleev? He arranged the elements by their atomic mass, which led to the discovery of new elements and predictions of their properties. Another interesting fact is that the most abundant element in the universe is hydrogen, making up about 75% of all normal matter. It is followed by helium, which makes up about 24% of the universe's mass. Have you ever wondered why gold is often used in jewelry? Gold is a highly malleable and ductile metal, which means it can be easily shaped into different forms without breaking. It is also a great conductor of electricity, making it useful in electronics. One of the rarest elements on Earth is astatine, with only a few ounces existing at any given time. It is highly radioactive and decays quickly, making it difficult to study. Lastly, the element mercury is the only metal that is liquid at room temperature. It is also known for its toxicity and was previously used in thermometers and barometers before being phased out due to health concerns. These fun facts about the Periodic Table and its elements showcase the fascinating world of chemistry and the diversity of materials that make up our universe.