{"id":221205,"date":"2025-05-29T09:08:01","date_gmt":"2025-05-29T09:08:01","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=221205"},"modified":"2025-05-29T09:08:03","modified_gmt":"2025-05-29T09:08:03","slug":"the-element-with-the-lowest-density-and-smallest-atomic-weight-is-which-one-of-the-following","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/05\/29\/the-element-with-the-lowest-density-and-smallest-atomic-weight-is-which-one-of-the-following\/","title":{"rendered":"The element with the lowest density and smallest atomic weight is which one of the following"},"content":{"rendered":"\n

The element with the lowest density and smallest atomic weight is which one of the following: (a) aluminum, (b) argon, (c) helium, (d) hydrogen, or (e) magnesium.<\/p>\n\n\n\n

The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n

The correct answer is: (d) hydrogen<\/strong>.<\/p>\n\n\n\n

\n\n\n\n

Explanation<\/strong><\/p>\n\n\n\n

Hydrogen is the element with both the lowest density<\/strong> and the smallest atomic weight<\/strong> among the listed options. Let’s explore why this is the case.<\/p>\n\n\n\n

Hydrogen (H) is the first element on the periodic table, with an atomic number of 1<\/strong> and an atomic weight of approximately 1.008 atomic mass units (amu)<\/strong>. It consists of only one proton and one electron (in its most common isotope, protium, it has no neutrons). This makes it the lightest element<\/strong> in existence.<\/p>\n\n\n\n

In terms of density<\/strong>, hydrogen gas at standard temperature and pressure (STP) has a density of about 0.08988 grams per liter (g\/L)<\/strong>, which is the lowest of all elements<\/strong>. Its extremely low mass and high velocity at room temperature cause hydrogen molecules to occupy a larger volume compared to their mass, resulting in very low density.<\/p>\n\n\n\n

Let\u2019s compare this to the other elements listed:<\/p>\n\n\n\n