401. For proper formation of teeth, Fluorine is essential.
402. The gas commonly known as “laughing gas” is Nitrous Oxide.
403. About 50% of the Earth’s crust, including the waters on the Earth and atmosphere, is Silicon.
404. Bronze medal is made up of metals Copper and Tin.
405. A light year is a unit of Length.
406. In Darwinism, Inheritance for acquired characters is not a part.
407. Hygrometer is used for measuring the Humidity of air.
408. Television signals are converted into light signals by Photo diode.
409. Sedimentary rocks are Porous.
410. The famous book of Ibn-Sina in which he discussed human physiology and medicine is Al-Qanun.
411. German Silver is an alloy of Cu + Ni.
412. Night vision is possible with the help of Infrared Rays.
413. Tibia is a bone found in the Leg.
414. The gland in the human body called the master gland is the Pituitary gland.
415. Leukemia is a disease of the Blood.
416. The beautiful color patterns exhibited by a peacock in its tail feathers are due to Selective reflection of light.
417. Stealth Technology refers to a coating which reduces the visibility of an aircraft on radar.
418. The cracking sound heard when dry hair is combed with a hard rubber comb is due to small electric sparks.
419. The concept “All motion is relative” was proposed by Albert Einstein.
420. The month of the calendar year that can lack a new moon is February.