In a heating curve, when is the temperature constant? need answers!
1.during a phase change

2.during a pressure change

3.during a change in kinetic energy

4.during a change in molecular velocity

The correct answer is Option 1.

Explanation:

For the given options:

Option 1: During a phase change

Whenever phase change occurs, the temperature remains constant because the heat is used to overcome the intermolecular forces between the particles.

Option 2: During a pressure change

As we know pressure is directly related to the temperature. So, if the pressure is increased, the temperature will also increase and vice-versa.

Option 3: During a change in kinetic energy

Kinetic energy is directly related to the temperature of a substance. So, if the kinetic energy is increased, the temperature will also increase and vice-versa.

Option 4: During a change in molecular velocity

Molecular velocity is directly related to the temperature of a substance. So, if the molecular velocity is increased, the temperature will also increase and vice-versa.

Hence, the correct answer is Option 1.

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: