1)the magnitude of the earthquake is measured on a Richter scale. A seismograph measures the intensity of an earthquake.

2) the scientific study of earthquakes is called seismology.

3)Biotic components include all living creatures like human beings, animals, insects, and plants, also

4)Abiotic components include all-natural non-living things like the sun, water, air, etc.

5)Communicable diseases:-Diseases transferred from an infected person to a healthy person by physical contact are called infectious diseases.

6) Non-communicable diseases:-the diseases which do not spread from an infected person to a healthy person are called non-communicable diseases. They are caused by a deficiency of some nutrients or bad habits.

7)Microorganisms:-microorganisms commonly known as germs, bugs, or microbes, are tiny living organisms that can not be seen with naked eyes.

8)mosquitos breed in stagnant water and spread malaria.

9)Peninsula:-an area of land surrounded on three sides by water is called a peninsula. The southern part of India is an example of a peninsula. It is triangular and surrounded by three-sided water- the Arabian sea, the Indian Ocean, and the Bay of Bengal.

10)Strait:-A strait is a narrow passage of water connecting two large water bodies like the sea and oceans. The Strait between India and Srilanka is Palk Strait

11)Isthmus:-A narrow strip of land joining two landmasses is called Isthumas. The Isthmus of Panama naturally connects the continents of North America and South America.

12)Satellite:-ASetellite is a celestial body that moves around the planets the same way the planets move around the sun.

13)Neil Armstrong was the first man to step on the moon’s surface in July 1969.

14)Mauna Kea (Hawaii) in the Pacific Ocean is an undersea mountain. It is higher than Mount Everest being 10,205 meters high.

15)Tributary:– A River or Stream which contributes its water to the main river by discharging it into the main river from either side.

16)Diseases:- Diseases caused by Microorganisms ——–

a)Virus:-Flu, common cold, measles

b)Bacteria:-cholera,Tuberculosis

c)Protozoa:-Malaria, sleeping sickness, Dysentery

d)Fungi:-Athlete’s foot, Ringworm, et

17)sand Dunes:-small hills of sand formed by blowing winds.

18)Dead sea:-this sea in Israel has a salinity of 340 grams per litre of water. Swimmers can float in it because the increased salt content makes it dense.

19)Tsunami is a Japanese word that means”Harbour waves “, as the harbours get destroyed whenever there is a tsunami.

20)March 22 is celebrated as World Water Day.