Science | GK Olympiad for Class 8 PDF Download

Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe. It encompasses a wide range of fields that explore the nature and behavior of natural things and the knowledge that humans derive from them.

Natural Sciences

These are the branches of science that study the natural world. They are divided into two main categories: life sciences (or biological sciences) and physical sciences.

Life Sciences (Biological Sciences)

• Biology: The study of life and living organisms, including their structure, function, growth, origin, evolution, and distribution.
• Zoology: The science of animals, studying their behavior, physiology, classification, and distribution.
• Botany: The study of plants, including their physiology, structure, genetics, ecology, distribution, classification, and economic importance.
• Microbiology: The study of microscopic organisms, such as bacteria, viruses, archaea, fungi, and protozoa.

Physical Sciences

• Physics: The study of matter, energy, and the interactions between them. Physics is fundamental to understanding the nature of the universe.
• Astrophysics: The branch of astronomy that deals with the physics of the universe, including the physical properties (like luminosity, density, temperature, and chemical composition) of astronomical objects.
• Geophysics: The physics of the Earth and its environment in space; also the study of the Earth using quantitative physical methods.

Chemistry

The science of the composition, structure, properties, and reactions of matter, especially of atomic and molecular systems.

• Organic Chemistry: The study of the structure, properties, composition, reactions, and preparation of carbon-containing compounds, which include not only hydrocarbons but also compounds with any number of other elements.
• Inorganic Chemistry: The study of the properties and behavior of inorganic compounds, which encompass metals, minerals, and organometallic compounds.

Formal Sciences

These are branches of knowledge that are concerned with formal systems, such as mathematics and logic, which use an a priori, as opposed to empirical, methodology.

• Mathematics: The study of numbers, quantities, shapes, and patterns and the logical operations by which unknown quantities are derived from known ones.
• Statistics: The study of the collection, analysis, interpretation, presentation, and organization of data.

Applied Sciences

Applied sciences use knowledge from the scientific fields to apply it practically, often resulting in new inventions or services.

• Engineering: The application of scientific, economic, social, and practical knowledge in order to design, build, and maintain structures, machines, devices, systems, materials, and processes.
• Mechanical Engineering: The design, construction, and use of machines.
• Chemical Engineering: The technology of scaling up chemical reactions for manufacturing purposes.
• Medicine: The science of diagnosing, treating, and preventing illness, disease, and injury.
• Neuroscience: The study of the nervous system, including the brain and spinal cord.

Here's a list of basic science terms, defined to help a class 8 student grasp foundational concepts across various branches of science:

1. Atom
The smallest unit of an element that retains the properties of that element. It consists of a nucleus containing protons and neutrons, surrounded by electrons.

2. Molecule
A group of two or more atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.

3. Photosynthesis
A process used by plants and other organisms to convert light energy, usually from the Sun, into chemical energy that can be later released to fuel the organisms' activities.

4. Ecosystem
A community of living organisms in conjunction with the nonliving components of their environment (things like air, water, and mineral soil), interacting as a system.

5. Force
An interaction that, when unopposed, will change the motion of an object. A force can cause an object with mass to change its velocity (which includes to begin moving from a state of rest), i.e., to accelerate.

6. Energy
The capacity to do work. It exists in various forms such as kinetic, potential, thermal, gravitational, sound, light, elastic, and electromagnetic energy.

7. Density
A measurement of how much mass is contained in a given volume. It is usually expressed in grams per cubic centimeter or kilograms per cubic meter.

8. Evaporation
The process by which water changes from a liquid to a vapor or gas. It is a key part of the water cycle and is triggered primarily by heat.

9. Condensation
The change of water from its gaseous form (water vapor) into liquid water. Condensation generally occurs in the atmosphere when warm air rises, cools and loses its capacity to hold water vapor.

10. Electricity
A form of energy resulting from the movement of charged particles (such as electrons or ions), used to provide power to electrical devices.

11. Magnetism
A physical phenomenon produced by the motion of electric charge, resulting in attractive and repulsive forces between objects.

Types of Devices 

Simple Machines

Devices that make work easier by allowing us to push or pull over increased distances.

Examples:

• Lever: A rigid bar pivoted around a fulcrum, used to lift or move loads. E.g., a seesaw or a crowbar.
• Wheel and Axle: A wheel attached to a rod (axle), used to carry loads over a distance. E.g., bicycles and cars.
• Pulley: A wheel on an axle designed to support the movement and change the direction of a cable or belt along its circumference. E.g., flagpoles and window blinds.

Electrical Devices

Devices that use electrical energy to perform tasks.
Examples:

• Light Bulb: Converts electrical energy into light and heat.
• Electric Motor: Converts electrical energy into mechanical motion.

Optical Devices

Devices that use light to view, enhance, or analyze.

Examples:

• Microscope: Uses lenses to magnify small objects.
• Telescope: Gathers light to view distant objects like stars and galaxies.

Fundamental Phenomena in Physics

Reflection

The phenomenon where light bounces back when it hits a reflective surface.

Examples:

• Mirror: Used to see one's own image.
• Echo: Sound waves reflecting off a surface and returning to the listener.

Refraction

The bending of light as it passes from one medium to another.

Examples:

• Lenses: Glasses lenses correct vision by refracting light to focus on the retina.
• Rainbow: Light refracting through water droplets in the atmosphere.

Diffraction

The spreading of waves around obstacles.

Examples:

• Holography: Uses light diffraction to create a three-dimensional image.
• Earphones: Sound waves diffract into the ear, allowing for private listening.

Famous Inventions in Science

The Light Bulb

• Inventor: Thomas Edison, 1879.
• Significance: Revolutionized night-time activities and extended productive hours past sunset.

The Telephone

• Inventor: Alexander Graham Bell, 1876.
• Significance: Made it possible to communicate instantly over long distances, changing how people and businesses operate.

Penicillin

• Discovery: Alexander Fleming, 1928.
• Significance: The first true antibiotic, which has saved countless lives from bacterial infections.

The Periodic Table

• Creator: Dmitri Mendeleev, 1869.
• Significance: Organized elements based on atomic mass, which later evolved to atomic numbers, predicting the discovery of new elements and their properties.