It is because Lithium has the smallest atomic radius of them all, because it has only two shells of electrons.So the small lithium nuclei, with their one positive charge each are more easily held together by the delocalised elextron cloud than the much larger sodium or potassium ions that still only have one positive charge each.potassium is more reactive owing to the loosely bound valence electron owing to a relatively more "electron shielding" effect.The valence electron is partially shielded from the attractive force of the nucleus by the inner electrons.Although lithium and potassium have one valence electron.The difference in hardness between lithium and potassium is primarily due to their atomic structures and bonding. Lithium has a smaller atomic radius and stronger metallic bonding compared to potassium. This makes lithium atoms more tightly packed and bonded, resulting in a harder substance compared to potassium.
because of its smaller size and high charge density.....
Lithium is softer than sodium. Sodium is harder because it has a higher atomic number and more electrons, which results in stronger metallic bonding compared to lithium.
Potassium has a higher first ionization energy than lithium because potassium has one more electron shell than lithium, making it harder to remove an electron from the outer shell. As electrons are added further away from the nucleus, the attractive force of the nucleus on the electrons decreases, requiring more energy to remove an electron from the outermost shell in potassium compared to lithium.
Calcium is harder than potassium primarily due to its atomic structure and bonding characteristics. Calcium has a higher atomic number and a stronger metallic bond, which results from its higher charge density and greater number of valence electrons contributing to stronger interactions between atoms. In contrast, potassium has a larger atomic radius and weaker metallic bonds, making it softer and more malleable. Additionally, the presence of more closely packed atoms in calcium contributes to its increased hardness compared to potassium.
Lithium hydride is more stable than other alkali hydrides because it has a higher lattice energy due to its smaller size and higher charge density. This results in stronger ionic bonding within the compound, making it more stable. Additionally, lithium hydride's crystal structure is more tightly packed than other alkali hydrides, contributing to its stability.
lithium plus. removing electron from something that is positive is much harder.
Among alkali metals, lithium ions have the lowest ionic mobility in water due to its smaller size and stronger attraction to water molecules. This results in greater hydration energy, which makes it harder for lithium ions to move in water compared to larger alkali metal ions like potassium or cesium.
No, iron is harder than potassium. Iron is a metal with a higher Mohs hardness rating than potassium, which is a soft alkali metal.
Rubidium is softer than potassium. This is because rubidium has larger atomic size and higher reactivity, which makes it more easily deformable when compared to potassium.
Cementite is harder than austenite because it is a compound of iron and carbon with a well-ordered crystal structure, whereas austenite is a solid solution of iron and carbon with a disordered structure. The ordered structure of cementite provides greater resistance to deformation and makes it harder.
Lithium holds onto its outermost electron more strongly than sodium due to lithium's smaller atomic size and higher nuclear charge. This results in greater attraction between the nucleus and the electron, making it harder for lithium to lose its outer electron compared to sodium.
Even though lithium fluoride is an ionic compound, it has a high lattice energy due to the strong interaction between the lithium and fluoride ions. This makes it harder for the compound to dissolve in water. Additionally, water molecules are not able to effectively solvate and separate the lithium and fluoride ions due to the strong lithium-fluoride bond.