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# Kinetic Energy and the State of Matter

The Relationship between Kinetic Energy and the State of Matter

Introduction
Kinetic energy and states of matter are two fundamental concepts that are closely related in the world of science. Kinetic energy is the measurement of work that an object does due to its motion. Anything that has mass and takes up volume is known as matter which exists in different forms such as solid, liquid, and gas. Differences in kinetic energy explain why matter exists in different forms. The relationship between the two is vital to understand how matter behaves and interacts with its environment. In this article, we will explore the relationship between kinetic energy and different states of matter, and how they influence each other.

Kinetic Energy and State of Matter
Kinetic energy is referred to as the energy that an object possesses due to its motion. It plays a vital role in understanding the behavior of matter. If we want to accelerate an object, we must apply some force. Applying force requires us to do work which in turn transfer energy to the object. kinetic energy depends on the mass and speed of the object. The following formula is used to calculate kinetic energy;

Kinetic energy = 1/2mv2

On the other hand, the state of matter refers to the physical form in which matter exists; that is solid, liquid, and gas. The state of matter of a substance is determined by the strength of the chemical bonds between its molecules and the energy of its particles.

How kinetic Energy Influences the State of Matter
Solid State
In the solid state, the matter is characterized by closely packed molecules and the distance between their particles is tiny that vibrate in place. As they do not have much space to move around that is why the particles in solids have little kinetic energy. However, they do have a specific vibrational energy that allows them to vibrate.
In a solid, the temperature determines the amount of kinetic energy its molecules have. When the temperature increases, the kinetic energy of the molecules also increases, causing them to vibrate more strongly. As more temperature increases, the kinetic energy overcomes the attractive forces between the molecules, and the solid form turns to a liquid state.

Fig.1 As temperature increases, kinetic energy more increases which turning ice cubes into water

Liquid State
In a liquid state, the matter is characterized by molecules that are loosely packed and can move around as well as slide past each other. The molecules in a liquid state have more kinetic energy as compare to that of a solid, and they can move more vigorously.

The considerable amount of kinetic energy allows the molecules to overcome the attractive forces between them, resulting in a more disordered state. When the temperature is high enough, the kinetic energy of the molecules increases which causes them to move faster. Consequently, the liquid turns into a gas state.

Fig.2 When the temperature is high enough, the kinetic energy more increases turning water (liquid state) into vapors (gaseous state)

Gas State
In this state, molecules are widely separated from each other and move around freely. The molecules in gases have the greatest amount of kinetic energy that allows them to move at high speed. This high level of kinetic energy is used to overcome all attractive forces between them, resulting in a highly disordered state. When the temperature is low enough, the kinetic energy of the molecules decreases, and the gas state turns into a liquid state.

Fig.3 The distance between molecules decreases as temperature decreases.

Phase Change
The relationship between kinetic energy and states of matter can also be seen in phase change. Phase changes occur when a substance turns from one state of matter to another. Two types of phase changes are mentioned below;

Endothermic Phase Changes
When energy is absorbed by the substance, increasing its kinetic energy, leads to the endothermic phase change. For instance, endothermic phase changes take place when solids turn into liquids and the liquids vaporize into gases.

Exothermic Phase Changes
Exothermic phase changes occur when energy is released by the substance, causing a decrease in kinetic energy. Examples that demonstrate exothermic phase changes are the freezing of liquids into solids and the condensation of gases into liquids.
Summary
• The relationship between kinetic energy and the state of matter is crucial in understanding the behavior of matter.
• Kinetic energy is defined as the energy that an object possesses due to its motion and it is the energy of the molecules that determines the state of matter.
• The state of matter can be changed due to any change in its kinetic energy such as condensation and sublimation.

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