Particulate Nature of Matter

HISTORY OF ATOM

JOHN DALTON

LEUCIPPUS

DEMOCRITUS

It was the Greek philosophers. Leucippus and Democritus, in the 5th century BC, had the idea that all matter consisted of small, uncuttable particles called atomos, which later came to be known as atoms. All forms of matter are made up of tiny particles that are in constant random motion. Scientists call this characteristic the particulate nature of matter. After more than 2,000 years, the ancient philosopher's idea about atoms became a theory. When John Dalton put together many observations and results of several experiments done by other scientists and formulated the Atomic Theory.

STATES OF MATTER

SOLID

LIQUID

GAS

SOLID

In an iceberg, the particles are packed closely together and vibrate a little in place but in fixed positions. Icebergs are considered solids because their particles are held together by strong forces. Solids have a definite shape and volume; they are incompressible. Why does a solid behave differently from a liquid or a gas? This question can be answered using the concept of the molecular structure of solids, liquids, and gases.

LIQUID

The particles of water are closer to one another than the gas particles, and they are in constant motion. Water in a glass is considered to be liquid because its particles move fast enough to overcome some of the attraction between them. The attraction between their particles is stronger than that between those in gases. Liquids do not have a definite shape, and just like gases, they take the shape of their container. The particles slide past one another but stay together.

SURFACE TENSION

Liquids have unique characteristics. A special property of liquids is surface tension. Surface tension is a force that acts on the particles at the surface of a liquid. Surface tension causes some liquids to form spherical drops, like the beads of water. Different liquids have different surface tensions. For example, cooking oil has a very low surface tension and forms flat drops.

VISCOSITY

Another important property of liquids is viscosity. Viscosity is a liquid's resistance to flowing; usually, the stronger the attraction between the particles of a liquid, the more viscous the liquid is. For example, if we drop a pebble in a container with honey, oil, and water, the pebble will sink to the bottom fastest in the container with water, followed by honey, and last in the container with oil. This is because oil is the most viscous liquid among the three, while water is the least viscous.

GAS

Consider the air inside a balloon: because the air particles inside the balloon are constantly moving and are far apart from one another, they are considered gases because they can move to any available space. When you inflate or deflate a balloon, its shape changes because air is a gas. Gas is a state of matter that has no definite shape or volume. The particles of a gas move very quickly, so they can break away completely from one another. There is less attraction between particles of a gas than between particles of the same element in the solid or liquid states.

PHASE CHANGE

Matter exists in three states: solids, liquids, and gases. A material will change from one phase to another depending on two factors. The temperature and the pressure when temperature changes phases of matter also change now.

MELTING

Let's take a look at the first phase change we call it melting a solid converts into a liquid when it's temperature is raised.

EVAPORATION

Next, there will be evaporation or boiling. Evaporation is a type of vaporization that occurs when only the surface of a liquid becomes a gas; therefore, evaporation is a phase change from liquid to gas.

FREEZING

After that is the freezing. Think about the liquid water becoming ice. Freezing or solidification is a phase change in which a liquid turns into a solid when its temperature is lowered below its freezing point. For example, water is frozen to solid ice by reducing the temperature. Just like this water becomes ice cubes.

CONDENSATION

Now, let's try to put some water in it. After some time, condensation happens. Condensation is the process in which a gas changes into a liquid when the temperature is decreased.

Now, let's try to put some water in it. After some time, condensation happens. Condensation is the process in which a gas changes into a liquid when the temperature is decreased.

Those droplets on a glass and the ice forming on a grassy field early in the morning are examples of condensation.

SUBLIMATION

After that we have sublimation. Sublimation is the process by which a solid transforms into a gas without passing through the liquid stage. Dry ice is a solid form of carbon dioxide that, when the temperature rises, changes directly into a gas.

DEPOSITION

Now the last one is deposition. Deposition is a process in which a gas transforms into a solid.
An example of this is the process of frost on leaves, where water vapor in the air surrounding the leaves loses its energy and changes into a solid.

The History of Chemistry Website by Sanchez Group

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