Tag: science & technology

Gravity is the force of attraction between any two objects that have mass. It's one of the four fundamental forces of nature. Force is a push or pull, acceleration is rate of velocity change, and work is force times distance.

Giraffes are the tallest living animals, with adults reaching 5.5 to 6 meters in height. Their exceptionally long necks allow them to reach leaves high in acacia trees. Elephants are the largest land animals by mass, but not the tallest.

NaCl is the chemical formula for sodium chloride, commonly known as salt. It's composed of sodium (Na) and chlorine (Cl) ions. Vinegar is acetic acid, pepper is a spice blend, and sugar is sucrose.

Einstein's famous equation is E=mc², where E is energy, m is mass, and c is the velocity of light. The speed of light squared (c²) is the conversion factor between mass and energy.

Mercury is the only metal that is liquid at standard room temperature (20-25°C). It has a melting point of -38.83°C and boiling point of 356.73°C. All other metals are solid at room temperature.

The atomic bomb dropped on Hiroshima on August 6, 1945 was code-named 'Little Boy.' The bomb dropped on Nagasaki on August 9, 1945 was called 'Fat Man.' Little Boy used uranium-235 while Fat Man used plutonium.

Autoclaves sterilize using saturated steam under pressure (typically 121°C, 15 psi for 15-20 minutes). The pressure allows steam to reach temperatures above 100°C without boiling, effectively killing all microorganisms including spores. Dry heat (A) requires higher temperatures (160-170°C) for longer durations.

Photobiology is the study of light's effects on living organisms, primarily focusing on visible and ultraviolet radiation. It encompasses photosynthesis, vision, photomorphogenesis, and light damage. Bioluminescence (D) is one phenomenon studied, but photobiology is broader than just organisms producing light.

Autoclaves sterilize using saturated steam under pressure, typically at 121°C for 15-20 minutes. The pressure prevents water from boiling at 100°C, allowing higher temperatures that kill all microorganisms. This method is more effective than boiling water (C) or dry heat (A).

The magnet test is a common field screening method for identifying stainless steel. Most stainless steel (austenitic grades like 304) is non-magnetic, so a magnet won't stick. However, some stainless steels (ferritic/martensitic grades) are magnetic, so this test isn't definitive but serves as a quick indicator.