Pure water is neutral with a pH value of 7 at 25°C. Values below 7 are acidic and above 7 are basic.

An adult human body has 206 bones. Infants are born with approximately 270 bones, many of which are cartilage.

Carbon dioxide (CO2) is the primary greenhouse gas responsible for global warming, released mainly through fossil fuel combustion.

Newton (N) is the SI unit of force. 1 Newton = 1 kg·m/s². Dyne is CGS unit, Joule is energy, Pascal is pressure.

Copper is an excellent conductor of electricity due to free electrons. Rubber, plastic, and ceramic are insulators.

All three represent the same freezing point of water: 0°C, 32°F, and 273.15 K are equivalent.

Vitamin D is synthesized by our skin when exposed to ultraviolet-B (UVB) radiation from sunlight.

Evaporation is the process where liquid water turns into water vapor/gas. This occurs at any temperature on the water's surface.

Distance is a scalar quantity as it has only magnitude. Velocity, acceleration, and displacement are vectors as they have both magnitude and direction.

Photosynthesis is the process where plants convert sunlight, water, and carbon dioxide into glucose and oxygen.