781. A chronometer measures time.
782. A stethoscope is used for hearing the sound of the heart and lungs.
783. Sound waves of frequency below 20 Hz are infrasonic waves.
784. Ultra-microscopic viruses are the main cause of measles.
785. The most soluble substance in water is sugar.
786. Milk contains about 87% water.
787. Sensory neurons carry messages toward the brain and spinal cord.
788. Coal is NOT an example of a renewable energy source.
789. The lifespan of red blood cells is approximately 120 days.
790. Deficiency of Vitamin-D results in rickets.
791. Sound waves are longitudinal waves.
792. At night, when photosynthesis is stopped, plants give off carbon dioxide.
793. A biosensor is used to measure blood glucose levels.
794. The carbon dioxide content in the atmosphere, by volume, is 0.039%.
795. Natural fats and oils are composed of carbon, hydrogen, and oxygen.
796. In the night, when photosynthesis is stopped, plants give off carbon dioxide.
797. The radioactive isotope of Uranium used in a nuclear bomb is 92 U 235.
798. The study of life in outer space is known as exobiology.
799. The founder of modern astronomy was Nicolas Copernicus.
800. The orbital period of the planet Mercury around the sun is 88 days.