What are the hardness, density, melting point, state, color, and chemical properties of alkali metal

From Encyclopedia (alkali metals).

The density of alkali metals increases with the increase of the number of nuclear charges, the metallicity is enhanced from top to bottom, the elemental reduction is enhanced, the melting and boiling point is reduced, and the density increases. Elemental metallic elements have strong elemental reducibility, cationic oxidation is weak, and elemental non-metallic is the opposite.

However, there is a special case where the density of potassium is less than that of sodium. For potassium, the nucleus gravitational pull on the outermost layer is smaller, and the effect of the increase in volume is greater than that of the increase in relative atomic mass, resulting in a smaller density of potassium than sodium.

Physical properties of alkali metals

The alkali metals are all silvery-white metals with metallic luster (cesium with golden yellow), but when exposed to air, oxide films will be formed due to the oxidation of oxygen, which will reduce the gloss and appear gray.

The density of alkali metal elements is less than that of typical light metals, lithium, sodium, potassium can float on water, and lithium can even float in kerosene.

The crystal structure of alkali metal elements is body-centered cubic packing, with small bulk density, Mohs hardness less than 2, soft quality, excellent electrical and thermal conductivity. Alkali metals can be alloyed with mercury (Hg) to form an alloy (amalgam).

The above content reference: Encyclopedia - alkali metals.

Alkali metalsThe law of density change is that it should have been increasing from top to bottom, but in fact the density of k is smaller than na, k is cubic cm na is cubic cm, these are these two anomalies.

The metallicity of alkali metals is enhanced from top to bottom, the elemental reducibility is enhanced, the melting and boiling point is reduced, and the density increases. The non-metallic properties of the halogen group are weakened from top to bottom, and the elemental oxidation is weakened.

weakens, the melting boiling point increases, and the density increases. The elements are metallic, delicate, elemental, reducible, and cationic.

Weak oxidation. The opposite is true for those with strong non-metallic elements.

Alkali metals all have one outermost electron belonging to the s orbital, so this group belongs to the periodic table.

S Zone. Chemical group properties of alkali metals.

It shows a very clear similarity with the elements of the same group and is a chemical element.

One of the illustrations of periodicity. Although hydrogen also belongs to group 1, its chemical properties are very different from those of alkali metals, so it is not generally considered to be an alkali metal.

Alkali metal characteristics

The alkali metal element is mostly a silvery-white metal with metallic luster (cesium with golden yellow), but when exposed to the air, it will produce an oxide film due to the oxidation of oxygen to reduce the gloss, showing gray, and the density of the alkali metal element is less than 2g·cm -3, which is a typical light metal, lithium, sodium, potassium can float on the water, and lithium can even float in kerosene.

The crystal structure of alkali metal elements is body-centered cubic packing, with small bulk density and Mohs hardness.

Less than 2, soft, excellent electrical and thermal conductivity. Alkali metals can be alloyed with mercury (Hg) to form an alloy (amalgam).

Alkali metals refer to the six metallic elements in group A except hydrogen (H) in the periodic table, namely lithium (Li), sodium (Na), potassium (K), rubidium (RB), cesium (CS), francium (FR).

where the density of lithium is, the density of sodium is, the density of potassium is, the density of rubidium is, the density of cesium is, and the density of francium is.

With the increase of the number of nuclear charges, the elemental melting and boiling point of VIIA group elements increases, and the elemental melting and boiling point of alkali metal elements decreases!

Alkali metals: belong to metal crystals, considered from the point of view of metal bonds.

From top to bottom, the radius of metal cations increases, the ability to bind electrons in the outer shell is weakened, and the metal bonds are weakened. The melting and boiling point decreases.

Halogen: belongs to molecular crystals, consider van der Waals forces.

From top to bottom, the relative molecular mass of the molecule increases, the van der Waals force increases, and the melting and boiling point increases.

The density of LI to CS is increasing, and the melting and boiling point is getting lower and lower.

F to I are becoming more and more dense, and the melting and boiling point is getting higher and higher.