Why Mg ion+2 is smaller than Mg

Rise in charge reduced the size due to rise in attraction between electron and nucleus.

Explanation:

Ion of magnesium is smaller than the atom of magnesium. As the nuclear charge increases, the attraction of electron to the nucleus increases in charged ions form of any element. Due to this increase in charge of magnesium ion,  the size of ion reduces

No. of electrons in Mg = 12

No. of proton in Mg = 12

Where as

No. of electrons in Mg2+ = 12

No. of proton in Mg2+ = 10

water   molecules stay close to each other through cohesion, the collective action of hydrogen bonds between water molecules. cohesion plants draw water upwards from the root through the stem's transport tubes (xylem) to the leaf. this transport occurs even in large trees and against gravity. transpiration, evaporation of water from plant leaves, creates a tension on water molecules being pulled up from the stem and roots.

water also has high (the attraction of one substance to another) properties because of its polar nature. adhesion of water molecules to plant cell walls counteract gravity while water is transported from roots to leaves.

water exhibits a very high surface tension when compared to other liquids. surface tension is a property of a liquid that holds the surface together and allows it to resist an external force. by capillary action, the water forms concave menisci inside the pores. the high surface tension of water pulls the concavity outwards, generating enough force to lift water from the roots to the leaves of plants.

thus, cohesion, along with adhesion and surface tension creates a capillary action that keeps water molecules interacting and moving through the plants out to the leaf cells.

therefore, option d) is the correct answer.

explanation:

o conteúdo de calor de um sistema é igual à entalpia apenas para um sistema que é constante