Class 7

Explained-hurricane

Hurricanes

Hurricanes are large, swirling storms. They produce winds of 119 kilometers per hour (74 mph) or higher. That’s faster than a cheetah, the fastest animal on land. Winds from a hurricane can damage buildings and trees. Hurricanes form over warm ocean waters. Sometimes they strike land. When a hurricane reaches…

water pollution explained

HOTS | Pollution & Plastics | Why should we not throw plastic bottles into the river?

Water pollution (or aquatic pollution) is the contamination of water bodies, usually as a result of human activities, so that it negatively affects its uses.  Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. Water pollution results when contaminants are introduced into these water bodies. Water pollution can be attributed to one of four sources: sewage discharges, industrial activities, agricultural activities, and urban runoff…

Why do Racing Cars have Flat Tyres?

Why do Racing Cars have Flat Tyres?

Have you ever wondered, why the racing cars have flat tyres ? Why are their tyres unique and flat as compared to those of regular cars? Let’s find out in this video , we address this question and will introduce you to special tyres known as “slick tyres. Who wouldn’t…

chlorophyll

How To Extract Chlorophyll From Leaves?

Chlorophyll  is any of several related green pigments found in the mesosomes of cyanobacteria and in the chloroplasts of algae and plants. Chlorophyll allow plants to absorb energy from light. Chlorophylls absorb light most strongly in the blue portion of the electromagnetic spectrum as well as the red portion. Conversely,…

Why Are Microorganisms Are Friends and Foes?

Why Are Microorganisms Are Friends and Foes?

Microorganisms are  living organism that is so tiny it can only be seen with the aid of a microscope. Consider that the largest human cells are about the diameter of a human hair. Bacteria cells are one-hundredth the size of a human cell and viruses are much, much smaller again. If you imagine that…

Heat - Understanding Conduction

Heat – Understanding Conduction

Thermal conduction is the transfer of internal energy by microscopic collisions of particles and movement of electrons within a body. The colliding particles, which include molecules, atoms, and electrons, transfer disorganized microscopic kinetic and potential energy when joined, known as internal energy. Conduction takes place in most phases: solid, liquid,…

Convection Experiment | Heat

Convection Experiment | Heat

Heat transfer is the transfer of heat or thermal energy between physical systems. So when there is a temperature difference between two bodies, heat is transferred from the hot body to the colder body. There are three common modes of heat transfer – conduction, convection, and radiation. In this article,…

osmosis experiment

What is Osmosis? |Potato Experiment

Osmosis is a vital process in biological systems, as biological membranes are semipermeable. In general, these membranes are impermeable to large and polar molecules, such as ions, proteins, and polysaccharides, while being permeable to non-polar or hydrophobic molecules like lipids as well as to small molecules like oxygen, carbon dioxide,…

thermos flask working

How Does A Thermos Flask Work?

The vacuum flask consists of two vessels, one placed within the other and joined at the neck. The gap between the two vessels is partially evacuated of air, creating a partial-vacuum which reduces heat conduction or convection. Heat transfer by thermal radiation may be minimized by silvering flask surfaces facing…

refrigeration cycle

Why Is The Back Of A Refrigerator Painted Black?

It could simply be that black paint is cheaper… But I believe that the external coils on the back of refrigerator are painted black for the following reason: There is a rule in nature that says “a color that is better at absorbing heat is also better at radiating heat.” …

Heat - Understanding Conduction

Heat

According to heat definition, it is one of the essential forms of energy for the survival of life on earth. Transfer of heat takes place from one body to another due to difference in temperature as per thermodynamics. We use heat energy for various activities like cooking, ironing, transportation, recreation,…

microorganism

Microorganism Part-2

A microorganism, or microbe, is an organism of microscopic size, which may exist in its single-celled form or as a colony of cells. The possible existence of unseen microbial life was suspected from ancient times, such as in Jain scriptures from sixth century BC India. Because microorganisms include most unicellular organisms from…

microorganism

Microorganism

A microorganism is a living thing that is too small to be seen with the naked eye. Examples of microorganisms include bacteria, archaea, algae, protozoa, and microscopic animals such as the dust mite. Microorganisms are found virtually everywhere, except for environments that have been made artificially sterile by humans. Even…

Maths geometry explained for kids

Geometry

Geometry  is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space that are related with distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is called a geometer. Main concepts The following are some of…

Maths geometry explained for kids (1)

Fibonacci Sequence

In mathematics, the Fibonacci numbers, commonly denoted Fn, form a sequence, the Fibonacci sequence, in which each number is the sum of the two preceding ones. The sequence commonly starts from 0 and 1, although some authors omit the initial terms and start the sequence from 1 and 1 or…

Light explained

Light

No single answer to the question “What is light?” satisfies the many contexts in which light is experienced, explored, and exploited. The physicist is interested in the physical properties of light, the artist in an aesthetic appreciation of the visual world.

Arithmetic Operations explained

Arithmetic Operations

The basic arithmetic operations are addition, subtraction, multiplication and division, although arithmetic also includes more advanced operations, such as manipulations of percentages, square roots, exponentiation, logarithmic functions, and even trigonometric functions, in the same vein as logarithms.  Arithmetic expressions must be evaluated according to the intended sequence of operations. There…

eukaryote prokaryotes

Cell Structure & Function

The cell is the basic structural and functional unit of life. Every cell consists of a cytoplasm enclosed within a membrane, which contains many biomolecules such as proteins and nucleic acids. Cells can acquire specified function and carry out various tasks within the cell such as replication, DNA repair, protein…

types of lever

Simple Machine

A mechanical device that changes the direction or magnitude of a force is known as a simple machine. In general terms, they are defined as simple mechanisms that make use of leverage or mechanical advantage to multiply force. Simple machines have few or no moving parts to modify motion and…

maths statistics explained

Statistics

Statistics is the science concerned with developing and studying methods for collecting, analyzing, interpreting and presenting empirical data. Statistics is a highly interdisciplinary field; research in statistics finds applicability in virtually all scientific fields and research questions in the various scientific fields motivate the development of new statistical methods and…

electric current explained

Electric current

  Current Current is the flow of particles in a particular direction. E.g air currents that cause winds or water currents. When particles flow in an electric circuit to produce electricity, it is called an electric current. Electric current The flow of electric charges in a circuit is called an…

Plants Reproduction

Reproduction in Plants

Plants reproduction is the production of new offspring in plants, which can be accomplished by sexual or asexual reproduction. Sexual reproduction produces offspring by the fusion of gametes, resulting in offspring genetically different from either parent. Asexual reproduction produces new individuals without the fusion of gametes. The resulting clonal plants…

types of lever

Simple Machine

  A simple machine is a mechanical device that changes the direction or magnitude of a force. In general, they can be defined as the simplest mechanisms that use mechanical advantage (also called leverage) to multiply force. Usually the term refers to the six classical simple machines that were defined…

Arithmetic Operations explained

Arithmetic Sequence

An arithmetic progression or arithmetic sequence is a sequence of numbers such that the difference between the consecutive terms is constant. For instance, the sequence 5, 7, 9, 11, 13, 15, . . . is an arithmetic progression with a common difference of 2. A finite portion of an arithmetic…

Space and astronomy explained

Astronomy and Space

  Astronomy is one of the oldest natural sciences. The early civilizations in recorded history made methodical observations of the night sky. These include the Babylonians, Greeks, Indians, Egyptians, Chinese, Maya, and many ancient indigenous peoples of the Americas. In the past, astronomy included disciplines as diverse as astrometry, celestial…

number line explained

Knowing Your Numbers

We use numbers in our day to day life. They are often called numerals. Without numbers, we cannot do counting of things, date, time, money, etc. Sometimes these numbers are used for measurement and sometimes they are used for labelling. The properties of numbers make them capable of performing arithmetic…

DNA explained

What controls our inherited traits?

Heredity is a process in which organisms acquire characteristics from their parents. These characteristics are called traits. Every individual is unique because they have a unique set of traits. The traits which are transmitted by the parent to its offspring during the process of fertilization are inherited traits. This inheritance…