The ductility of a material is the measure of a) the amount of elastic deformation that can be sustained before yielding b) the capacity of a material to absorb energy when it is deformed elastically c) the degree of plastic deformation that has been sustained at fracture. d) the amount of elastic and plastic deformation that can be sustained before reaching the tensile strength

a) the amount of elastic deformation that can be sustained before yielding

Explanation:

ductil material is understood as the one that undergoes great deformations before breaking, it's a property that as such manifests itself once the material is supporting a considerable force.

about the ductility of a material:

→ the percentage of elongation

→ the percentage reduction in the area

h let me think

alkaline metals are lithium, sodium, rubidium, potassium, cesium and francium.

alkali metals have electronegativity from 0.7 to 1, lowest in periodic table of elements, which means that alkali metals (i group in periodic table) has positive oxidation number in compounds.

electronegativity is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.

alkaline metals (far left in main group) have lowest ionizations energy and easy remove valence electrons,

for example, potassium is the alkali metal and has a single valence electron in the outer electron shell.

electron configuration of potassium is: ₁₉k 1s²2s²2p⁶3s²3p⁶4s¹.

they can not exist alone in nature, because they are very reactive.