Question

.
1
Alkali and alkaline earth metals show increasing
trend down the group in
A atomic volume B. electropositivity
C. atomic radii D. all above​

Answer 1

Answer:

GENERAL CHARACTERISTICS OF ALKALI AND ALKALINE METALS - DEFINITION

Alkali metals are highly reactive elements. They are soft, have low density, low melting point, low boiling point, give characteristic colour to the flame, are strongly electro-positive character. They react with water liberating H

2

and react with acids replacing hydrogen.

Alkaline earth metals have higher density, higher melting point, higher boiling point, have less electropositive character and are less reactive. It reacts with water liberating H

2

. They reacts with acids less vigourously than alkali metals displacing hydrogen.

GENERAL CHARACTERISITIC OF ALKALI METALS - DEFINITION

Ionization enthalpies of alkali metals are low and decrease down the group from Li to Cs. Melting and boiling point of alkali metals are high.

ATOMIC PROPERTIES OF ALKALI METAL - DEFINITION

The alkali metal atoms have the largest size in their respective periods of the periodic table. Atomic radii and ionic radii increase with atomic number as we move from Li to Cs.

PHYSICAL PROPEERTIES OF ALKALI METALS - DEFINITION

All the alkali metals are soft and have low densities, melting and boiling points, as well as heats of sublimation, vapourisation, and dissociation. They all crystallize in the body-centered cubic crystal structure, and have distinctive flame colors, because their outer s-electron is very easily excited.

ATOMIC PROPERTIES OF ALKALINE EARTH ELEMENTS - DEFINITION

The atomic and ionic radii of the alkaline earth elements are smaller than those of the corresponding alkali metals of the same period. This is due to increase in atomic number as well as increased nuclear charge in these elements.

PHYSICAL PROPERTIES OF ALKALINE EARTH ELEMENTS - DEFINITION

shiny.

silvery-white

somewhat reactive metals at standard temperature and pressure.

readily lose their two outermost electrons to form cations with a 2

+

charge.

low densities

low melting points

low boiling points