At 25.0c helium molecules have an average velocity of 1.26x10^5 cm/s and methane molecukes have an average velocity of 6.30x10^4 cm/s calculate the kinetic energy of each type of molecule at 25.0c and determine which is greater

Explanation:

The average  kinetic energy of gas particles depends only on the temperature. Thus you must expect that the average kinetic energies of both helium gas and methane gas at 25ºC are equal.

1. Kinetic energy of helium molecules

    The mass of 1 mole of molecules of helium is 4 grams. Convert to kg, to use SI units: 0.004 kg

   Convert the velocity to m/s: 1.26×10⁵ cm/s = 1.26 × 10³ m/s

2.  Kinetic energy of methane molecules

    The mass of 1 mole of molecules of methade is 416 grams. Convert to kg, to use SI units: 0.016 kg

   Convert the velocity to m/s: 6.30×10⁴ cm/s = 6.30 × 10⁴ m/s

As expected both average kinetic energies are the same.

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: