Which alkali metal has lowest heat of atomisation?

Lithium is the smallest element in the group and has the highest ionization energy, mp and heat of atomization; it also has the lowest density of any solid at room temperature.

Why do alkali metals have low ionisation enthalpy?

The valence electrons in alkali metals, are very away from the nucleus. They can easily lose electrons with low energy and become cationic. Hence, they have low ionization energy.

Why does enthalpy of atomisation decrease down a group?

Enthalpy of atomisation depend upon the number of unpaired electron more is unpaired electron more is enthalpy of atomisation. Upto the middle of the series, the number of unpaired electrons increases and then decreases due to their pairing.

Why are alkali metals Univalent?

All alkali metals have only one electron in their valence shell. They exhibit an oxidation state of +1 in their compounds and can lose the single valence electron readily to acquire the stable configuration of a noble gas. Thus, alkali metals are univalent and form ionic compounds.

Which alkali metal has the lowest ionization energy?

cesium
Of the 5 non-radioactive alkali metals, cesium has the lowest melting and boiling point, the highest density, the largest atomic radius, and the highest reactivity. It has the lowest electronegativity and the lowest first ionization energy.

Which element among the alkali metals has the lowest ionisation enthalpy?

The ionization energies of alkali metals decrease progressively as we move down the group due to addition of new shells. Since Rb is at bottom position among the given elements hence, it has the lowest ionization energy among the given elements.

Why do alkali metals have low density?

Since alkali metals have a large atomic size and low atomic weight, they have low density.

What is the enthalpy of atomisation explain?

Definition. Enthalpy of atomization is the amount of enthalpy change when a compound’s bonds are broken and the component atoms are separated into individual atoms. Enthalpy of atomization is denoted by the symbol ΔatH.

What is the difference between enthalpy of atomisation and enthalpy of dissociation?

The key difference between enthalpy of atomisation and bond dissociation is that enthalpy of atomisation describes the energy required to separate a molecule into its atoms whereas the enthalpy of bond dissociation describes the dissociation of chemical bonds in a molecule.

Why are alkali metals always Univalent which alkali metal ions form largest hydrated ion in aqueous solution?

Li+
Which alkali metal ion forms largest hydrated ion in aqueous solution? Answer: They are always univalent because after losing one electron, they aquire nearest inert gas configuration.Li+ forms largest hydrated cations because it has the highest hydration energy.

Why alkali metals are good reducing agents?

Alkali metals are known as good reducing agents because they have their only one valence electron in their outermost shell. Hence, it makes it easy for alkali metals to lose their outermost electron and attain a nearest noble-gas configuration and become more stable. This makes alkali metals a strong reducing agent.

Why do alkali metals have low ionisation enthalpy values?

Low values of ionisation enthalpies are due to increase in atomic number,size,nuclear charge and increase in shielding effect. Alkali metals have only one valence electron. The rest are all core electrons. The net charge on the core is a good estimate of what that line outer electron feels.

Why do alkali metals have an exothermic electron affinity?

Why do alkali metals have an exothermic electron affinity? Alkali metals should have positive electron gain enthalpy as they are electropositive elements and also there atomic size is big in their periods so they should be reluctant to take electrons but they show negative electron gain enthalpies. Why?

Why are alkali metals univalent electropositive metals?

Alkali metals shall donate the single valence electron to get a noble gas configuration. Thus they are all univalent electropositive metals. Ionization energy needed for the removal of the valence electron will be highest for the small lithium atom.

Which of the following metals has negative electron gain enthalpy?

So Alkali metals has negative electron gain enthalpy. All alkali metals have negative electron gain enthalpy.