What is the cause of matured leaves and fruits falling?

When plants reach maturity, why do their leaves and fruits fall off?

You can tell the difference between a broken leaf stalk and a naturally fallen leaf stalk by looking at their abscission layers. As fruits and leaves mature, the amount of growth substances they contain decreases, which is why an abscission layer is created. Therefore, plants lose their fruit and their leaves.

Phenomenon of Lightning and thunder

A cloud to ground lightning voltage is approximately 10 million volts. A current of nearly 25 000 amperes flows in such lightning. The voltage of a household LED lamp is 230 volts, while the current flowing through it is less than 0.1 amperes. As a result, you will be able to determine how high the voltage and current of a lightning strike are.

When such a large current flows through air in such a short period of time (about 10 milliseconds), the air is heated to extremely high temperatures. This temperature is approximately 30 000 0C. It has a temperature five times that of the sun’s surface.

Because of the high air temperature, the area around the lightning current expands instantly (same thing happens when a cracker explodes). When air expands all at once like this, a wave is produced first, followed by a sound wave. Thunder is the result of the sound wave.

Light and sound are created simultaneously by lightning. However, light is perceived first, followed by sound. The reason for this is that the speed of light is extremely fast, whereas the speed of sound is much slower. Because light travels at such a high speed, light travel from the location where lightning occurs to us is negligibly small. It takes longer for sound to reach us. That is why sound arrives later.

Phenomenon of Cyclones

A region of low pressure develops when the air pressure at a particular location in the atmosphere closer to the surface of the Earth drops below the pressure that is found in the surrounding areas of that location.

If this state of low pressure continues to worsen, it will eventually turn into a depression. If the situation continues to drop, it will eventually lead to a cyclone.

Phenomenon of Bimetallic strips

Bimetallic strips, which are comprised of two different metals and have different expansion rates for a given temperature difference, are used to regulate the temperature in electrical appliances such as electric irons and rice cookers. These strips are used to control the temperature of the appliance. It is made up of two metallic strips that have unequal expansions and are riveted together in a very rigid manner. While one of its ends is securely attached to a piece of metal, the other end is free to move in any direction. One of the strips in the bipolar strip expands more than the other when the temperature of the strip is raised. After that, the two strips make a bend.

Phenomenon of sea breeze

The specific heat capacity of the earth’s surface on land is less than that of sea water. As a result, during the day, the land surface heats up faster than the sea water. The air near the land surface then warms, decreasing density and causing the air to rise.

This lowers the pressure close to the ground. The air mass then flows from the sea to the land. This is known as sea breeze.

Phenomenon of land breeze

Both the land and the sea cool down at night. The sea cools slowly, whereas the land cools quickly. The air near the sea surface is warm, while the air above is cold. As a result, the air near the sea moves upward, creating a low pressure region just above the sea. The wind then blows from the land side to the sea to equalize the pressure difference. This is referred to as land breeze.

Phenomenon of Acid rain

Rain is naturally acidic due to the dissolution of carbon dioxide and nitrogen dioxide (NO2). The pH of natural rain water is around 5.6. When the pH of the rain lowers, the acidity of the rain increases. The increase in acidity in rain is caused by an increase in Sulphur dioxide, Sulphur trioxide, and nitrogen dioxide in the atmosphere.

Sulphur dioxide is water soluble, so it reacts with water to form sulphurous acid (H2SO3). This sulphureous acid oxidizes further to form sulphuric acid (H2SO4). Sulphuric acid is also formed during the dissolution of Sulphur trioxide. Nitrogen dioxide contributes to the acidic nature of rain. Nitric acid is formed when it reacts with water. When water combines with the abovementioned acids to generate rain, acid rain is formed.

Phenomenon of Global warming

The greenhouse effect is caused when there is a high concentration of polyatomic molecules of greenhouse gases in the atmosphere. These gases include carbon dioxide, methane, and various chlorofluorocarbons (CFCs). When the levels of greenhouse gases on Earth are allowed to rise above the safe threshold, a significant amount of the solar energy that the planet receives is deflected away from it. As a direct result of this, the temperature of the atmosphere rises. This phenomenon is referred to as global warming.

Phenomenon of Depletion of ozone layer

Ozone is a trimetric oxygen molecule. This is a thin layer found 25 kilometers above the earth’s surface. At higher elevations, oxygen absorbs UV energy and converts it to atomic oxygen. This type of atomic oxygen is extremely reactive. They combine with O2 to form O3. This O3 is converted back to O2, preserving natural equilibrium. This ozone layer acts as a protective shield, preventing harmful UV radiation from reaching the earth’s surface. However, gases such as CFCs and nitric oxide (NO) deplete the ozone layer by detaching O2. At higher altitudes, CFC absorbs solar radiation and is converted to atomic chlorine. When this atomic chlorin reacts with O3, it degrades ozone molecules. Similarly, nitric oxide destroys ozone by reacting with it.

As the ozone layer depletes, holes appear in it. As a result, high-energy radiation reaches the earth’s surface.

The consequences of ozone layer depletion.

  • Cataracts are caused by
  • Mutations that cause
  • Reduce the body’s immunity
  • Reduce crop yield by interfering with photosynthesis

Phenomenon of Photo chemical smog

It is a yellow-colored mist that is produced as a result of a reaction that is caused by sunlight and the chemicals that are emitted by vehicles. This mist is the source of eye irritation and can impair vision.

Negative effects brought on by photochemical smog

  • Disorders of the respiratory tract such as coughing and wheezing are caused.
  • harmful to the plants. Therefore, there is an impact on the growth of plants and the production of food.
  • Turbidity causes difficulties with one’s vision.
  • Bleaching has a detrimental effect on the quality of rubber as well as clothing.

Phenomenon of eutrophication

The presence of waste products from industries, agrochemicals, fecal matter, and detergents all contribute to an increase in the concentration of phosphate and nitrate in reservoirs. Because of this, there is an excessive growth of algae, which results in the formation of a foamy layer that is green in color. The term for this kind of thing is “eutrophication.” Competition causes the overpopulation of algae to result in their death, which is then consumed by anaerobic bacteria. Eutrophication of reservoir matter results in the emission of odorous gases such as hydrogen sulfide (H2S), ammonia (NH3), and methane (CH4).

Aspects detrimental to eutrophication

  • Water’s decreasing ability to be seen through
  • Incapable of making use of the water
  • a lessening of the biological variety as a result of the loss of aquatic plants and animals
  • deterioration of the aesthetic value of reservoirs

Phenomenon of Bio magnification

Bioaccumulation is the process by which a substance, such as a pollutant, builds up in an organism. The increasing concentration of a substance as it moves up the food chain is referred to as biomagnification. This is possible due to the fact that each level of the food chain consumes the organisms from the previous level, thereby consuming any pollutants or toxins present in those organisms. This can result in increased levels of the substance in organisms at the top of the food chain.

Biomagnification is indicated by the accumulation of the pesticide DDT in birds of prey. In the middle of the 20th century, DDT was widely used to control crop pests. However, the pesticide was not easily broken down in the environment and subsequently entered the food chain. The pesticide was applied to smaller organisms, such as insects, which were then consumed by larger organisms, such as fish. Birds, including birds of prey such as eagles and ospreys, then consumed the fish. These top predators had the highest levels of DDT in their bodies, which were frequently harmful or even lethal. This phenomenon, known as biomagnification, is one of the reasons why DDT has been banned in numerous countries.

Phenomenon of Eclipse

Lunar eclipses

There are more lunar eclipses that can be seen than there are solar eclipses that can be seen in our lifetimes. Lunar eclipse occurs on a full moon day. When the Earth moves into position between the sun and the moon while they are aligned in a straight line, a lunar eclipse will take place.

Solar eclipses

Every 27.3 days, the moon revolves around the Earth.

On some occasions during this journey, the moon’s shadow falls on the earth. The sun is completely or partially invisible to those who spend time in the shadows. This is known as a solar eclipse. The size of the sun and the moon are equal in the sky (as our eyes can see). It is a large object, the sun. When compared to the sun, the moon is extremely small. However, the sun is very far from the earth and the moon. That is why they appear to be roughly the same size.

As a result, during a solar eclipse, the moon can completely obscure the sun. In the earth’s shadow cast by the moon, two areas can be identified. These are known as the umbra and penumbra.

Phenomenon of Heat radiation

Because heat travels towards our body via radiation, we experience warmth when we are in close proximity to a fire or another heated object. Any object that is heated will radiate heat.

Radiation is a method of heat transfer that does not involve the participation of the particles that make up a medium in any way. Radiation is the means by which heat is transmitted from the sun to the earth.

Phenomenon of Convection

You may have noticed that some of the tree branches high above a large fire are swaying back and forth. What could possibly be the explanation for this?

The hot air immediately surrounding the fire rises, while cooler air from lower levels flows upwards toward the flames. Convectional currents are so-called because they involve the upward movement of heated air currents. The twigs of the trees will begin to wave when they come into contact with these currents.

Phenomenon of Conduction

When placed in a cup of hot tea, a metal spoon quickly warms up. When a metal spoon is placed into a pan that is being heated by a cooker, the opposite end of the spoon will become hot.

The heat travels from one particle to the next as it circulates. The term “conduction of heat” refers to the process by which heat is transferred from one particle to another within a solid without the movement of the particles themselves.

The majority of metals are excellent heat conductors. These materials are referred to as heat conductors.

Phenomenon of Speed of sound

When we are submerged in water, the sound that dolphins produce can be picked up with greater clarity by our ears. However, the same sound that they emit above water can only be heard very faintly by humans. This is due to the fact that sound travels through water at a much quicker rate than it does through air.

Because there is no air in space for sound waves to travel through, astronauts who are communicating with one another cannot hear each other. Therefore, it should come as no surprise that sound does not travel through vacuum; rather, it must have a medium in order to do so.

Phenomenon of Cumulo nimbus clouds

Closer to the stratosphere, the Cumulo nimbus takes the shape of an anvil. This shape is caused by the wind blowing in only one direction. Rain, thunder, and lightning are possible after these types of clouds form.

Phenomenon of Aurora

Auroras, also known as the northern and southern lights, are displays of natural light that occur in the upper atmosphere of the Earth. The interaction of the solar wind, a stream of charged particles emitted by the sun, with the Earth’s magnetic field causes them. When the solar wind reaches the Earth, it can excite the charged particles in the upper atmosphere of the planet, causing them to emit light. Typically, the light is green, but it may also be red, yellow, blue, or purple. Auroras are most frequently observed in the polar regions, close to the magnetic poles of the Earth.

The thermosphere is where the unique natural phenomena known as Aurora borealis and Aurora australis both takes place. Aurora borealis and Aurora australis can be observed near the northern and southern poles, respectively.

Phenomenon of Rainbow

Rainbows are caused by light refraction and reflection as it passes through air water droplets. When sunlight enters a droplet of water, it slows down and bends, or refracts, at a specific angle. The light then reflects off the droplet’s inner surface and refracts again as it exits the droplet. This results in a color spectrum, with red on the outside and violet on the inside. A rainbow’s colors are arranged in the following order: red, orange, yellow, green, blue, indigo, and violet. Rainbows appear when the sun, the observer, and the water droplets align in a specific way, which is why we see them most often after a rain.

Phenomenon of Radioactivity

The process by which the nuclei of certain atoms emit particles and energy in the form of electromagnetic waves or radiation is referred to as radioactivity. The instability of the atomic nuclei causes this process.

Uranium and plutonium, which are used as fuel in nuclear power plants, are examples of radioactive materials.

Radium and radon, both of which can be found in trace amounts in rocks and soil

Carbon-14 is a chemical element that is used in carbon dating to determine the age of fossils.

Iodine-131, a trace amount of which is used in medical treatments such as thyroid cancer therapy

Americium-241 is a metal found in smoke detectors.

Cesium-137 is a byproduct of nuclear reactions that can end up in the environment as a result of nuclear accidents or weapon testing.

It is important to note that all of these examples are hazardous to human health if not handled properly, as they can cause cancer and other health problems if large enough amounts enter the body.

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Anuradhika Lakmali

Anuradhika Lakmali is a co-founder of Science A Plus learning network. She is working as a government teacher and has interest in chemistry, biology, phisics and self development.