Physical and Chemical Changes

Every day around us we see various kinds of physical and chemical changes such as tree growth, rising and falling of the sun, shape and size of the moon, burnable paper, coal, tree. But did you try to understand the change? Let's take a closer look at this concept.

Before understanding the scientific cause of change, you need to understand the terms physically, chemically, reversibly and irreversibly. These are not random! There are many reasons for these physical and chemical changes.

Physical features: it is called the shape, size and state of matter. For example, if you take a piece of paper and fold it down, its shape will change. This form of change is a physical property. Examples include tearing paper, melting wax, melting ice in water, cooling water, turning water into steam evaporation, steam into water condensation, stretching a rubber band

Chemistry: It is the essential nature of matter. For example, since milk is a product of milk, you can get cards from milk, but the internal characteristics of each type of milk are totally different. Example: burnable paper, fuel, wood, etc.

Reversible: You can reverse things and processes. This is called reversible. For example, if folded paper is folded into paper, you can also enlarge it. Therefore, folding a piece of paper is a reversible process. Likewise, hydrogen and oxygen can be recovered from water.

Irreversible: There are things and processes called irreversible. For example, when making tofu from milk, then making tofu from tofu, you can not make milk. So this is an irreversible process.

There are two types of material change: physical change and chemical change. As its name implies, physical changes affect the physical properties of substances and chemical changes affect the chemical nature of the substance. Many physical changes are reversible (such as heating and cooling), but chemical changes are usually irreversible, or can be reversed only by additional chemical changes. Another way of thinking is that substances are not fundamentally different substances due to physical changes, but substances may become chemically new substances due to chemical changes. For example, there are two physical changes in a mixed smoothie. To change the shape of each fruit and to mix various fruits. During the mixing process, there is no change in the chemical substances in the smoothie ingredients (for example, vitamins in water and water do not change), so it can be seen that there is no chemical change.

All substances have different physical and chemical properties and may undergo physical or chemical changes. Physical properties such as hardness and boiling point, and physical changes such as melting and freezing do not include changes in the composition of the substance. Chemical properties such as flammability and acidity and chemical changes such as rust involve the generation of substances different from existing materials. Measurable attributes fall into two categories. The wide nature depends on the amount of material present, such as the quality of gold. Reinforcement does not depend on the amount of material present, such as the density of gold. Heat is an example of wide nature, temperature is an example of intensive nature.

The change between the states of the substance can be a physical change or a chemical change. In physical change, even though the physical properties change, the chemical formula of the substance remains the same. Physical properties include taste, aroma, texture, color and so on. Normally, body changes can be restored. Ice can dissolve in liquids, which can be refrozen to a solid state. In each state, the chemical formula of water, H2O has not been changed. Another example of a physical change is the use of a paint, crayon or marker for filtering, cutting, melting and coloring the surface of something. Examples of physical changes are shown in Figure 2 and Figure 3. 6 A and B