Science
Science · sanalda.comWhat is Solar system?
The solar system consists of the Sun and the planets, moons and other celestial objects bound to it by gravity.
Science · sanalda.comWhat is Earth?
Earth is the third planet from the Sun and the only planet known to support life.
Science · sanalda.comWhat is Moon?
The Moon is the natural satellite of Earth. It appears bright in the sky because it reflects sunlight.
Science · sanalda.comWhat is science?
Science is a shared research activity that uses systematic observation, measurement, reasoning, evidence gathering and critical testing to produce reliable knowledge about nature, society and human beings. It is not merely a collection of memorized facts; it is a dynamic process in which questions are stated clearly, claims are tested against evidence, methods can be scrutinized by others, and conclusions are revised in light of new findings.
Science · sanalda.comWhat is Earthquake?
An earthquake occurs when stress accumulated in the Earth's crust is released by the breaking of rock or sudden movement along an existing fault, sending energy outward as seismic waves. The shaking felt at the surface is not the earthquake itself but the motion created as that released energy travels through the ground and structures. An earthquake is a natural event; the scale of death and damage is strongly related to the strength of buildings, ground conditions, settlement patterns, preparedness and correct protective actions.
Science · sanalda.comWhat is the scientific method?
The scientific method investigates questions about nature through observation, measurement, testable explanations and critical evaluation. It is not one rigid sequence: laboratory experiments, field observations, historical records and computer models suit different questions. Their shared purpose is to compare claims with evidence that can be assessed independently of personal opinion.
Science · sanalda.comWhat is an atom?
An atom is the smallest unit retaining an element’s chemical identity. It consists of a positively charged nucleus and electrons occupying quantum states around it. Everyday materials depend on the kinds of atoms present, their electronic arrangements and their interactions. An atom is not an indivisible solid sphere; it has smaller constituents.
Science · sanalda.comWhat is a molecule?
A molecule is an identifiable unit of two or more chemically bonded atoms. The kinds and numbers of atoms matter alongside their connections and three-dimensional arrangement. Water, oxygen and carbon dioxide are molecular substances. However, not all matter consists of separate molecules: ionic crystals and metals have different arrangements.
Science · sanalda.comWhat is the periodic table?
The periodic table arranges elements by increasing atomic number and reveals recurring chemical properties. This organization is related to atomic electron structure. Beyond memorizing names, the table helps predict similarities, bonding tendencies and changes in certain properties.
Science · sanalda.comWhat is force?
Force describes an interaction between objects that can change motion or shape. It is a vector, possessing direction as well as magnitude, and its SI unit is the newton. Several forces may act on one object; their vector sum, the net force, determines how its motion changes.
Science · sanalda.comWhat are motion and acceleration?
Motion is a change in position over time relative to a chosen reference frame. Acceleration is the rate at which the velocity vector changes. Position, speed and changes in motion are described by distinct quantities. These distinctions provide a shared language for phenomena from braking vehicles to planetary orbits.
Science · sanalda.comWhat is energy?
Energy is a fundamental quantity used to describe physical systems and changes in them. Different forms are associated with motion, position, temperature, chemical structure and radiation. Its SI unit is the joule. Rather than an invisible fluid, energy is a concept relating measurable changes quantitatively.
Science · sanalda.comWhat is thermodynamics?
Thermodynamics studies relationships between energy transfer, temperature, work and matter’s large-scale behavior. Its tools help explain engines, refrigerators, the atmosphere and energy balance in living systems. It uses macroscopic quantities such as pressure, volume and temperature rather than tracking every particle.
Science · sanalda.comWhat is electromagnetism?
Electromagnetism studies electric charges and their relationships with electric and magnetic fields. Static electricity, magnets, electric currents and light are different expressions of the same fundamental interaction. Electronics, power generation and communication technologies rely on these relationships.
Science · sanalda.comWhat is light?
Light is electromagnetic radiation, although everyday usage usually means the visible range detected by human eyes. Physics also examines invisible radiation such as infrared and ultraviolet within the same framework. Light carries energy and momentum, and explaining it requires both wave and quantum properties.
Science · sanalda.comWhat is sound?
Sound consists of pressure and motion changes carried by mechanical waves through a medium. A vibrating source disturbs nearby matter, which transfers the disturbance onward. Human hearing detects only certain ranges of frequency and intensity. Producing, transmitting and perceiving sound are distinct stages.
Science · sanalda.comWhat is quantum physics?
Quantum physics explains the behavior of atoms, electrons and light. It provides experimentally testable probabilistic predictions where classical intuition fails. Its effects are not restricted to tiny particles: semiconductors, lasers and some large-scale states of matter also require quantum principles.
Science · sanalda.comWhat is relativity?
Relativity names two connected theories describing space, time, motion and gravity. Special relativity relates inertial reference frames, while general relativity treats gravity through spacetime geometry. They do not claim that everything is subjective: they define precise relationships between different observers’ measurements.
Science · sanalda.comWhat is DNA?
DNA, or deoxyribonucleic acid, is the principal hereditary information molecule in cellular life. Information resides in nucleotide sequences and influences processes such as RNA and protein production. An organism’s characteristics cannot all be reduced to one sequence: gene activity and environmental interactions also matter.
Science · sanalda.comWhat is a cell?
A cell is the fundamental structural and functional unit of life. Some organisms, including bacteria, are single-celled; plants and animals contain many specialized cells. Cells maintain boundaries, exchange materials, transform energy and use genetic information. These are coordinated processes within a regulated whole.
Science · sanalda.comWhat is evolution?
Evolution is change in heritable characteristics of populations across generations. It is a central biological framework explaining diversity and relationships among organisms. It differs from changes occurring within one individual’s lifetime. Evolutionary processes involve inherited variation interacting with reproduction and environmental conditions.
Science · sanalda.comWhat is photosynthesis?
Photosynthesis uses light energy to drive biological chemical transformations. Oxygenic photosynthesis in plants, algae and cyanobacteria involves producing organic matter from carbon dioxide and using water. It is fundamental to understanding much of Earth’s food webs and the biological source of atmospheric oxygen.
Science · sanalda.comWhat is a black hole?
A black hole is a region of spacetime from which even light cannot reach the outside once inside its event horizon. It involves strong gravitational effects associated with mass concentrated into a small region. It is not a cosmic vacuum cleaner pulling everything in from unlimited distances: effects depend on mass, distance and an object’s motion.
Science · sanalda.comWhat is the Big Bang?
The Big Bang model describes an earlier, much hotter and denser universe that expanded and cooled. It is not an ordinary bomb exploding into preexisting empty space. It explains large-scale cosmic development without by itself settling every question about an absolute beginning of time or why a universe exists.
Science · sanalda.comWhat is a star?
A star is a hot sphere of plasma held together by its own gravity and powered during much of its life by nuclear fusion in its core. The Sun is a star. Stellar colors, luminosities and lifetimes differ; two similar points of light can have very different physical properties.