Questions

A Disease which spreads by contact are Contagious.

Infectious diseases : These are caused by microscopic germs such as bacteria or viruses that get into the body and cause problems. Some but not all infectious diseases spread directly from one person to another. Infectious diseases that spread from person to person are said to be contagious. Some infections spread to people from an animal or insect, but are not contagious from another human. 

Contagious diseases such as the flu, colds, or strep throat spread from person to person in several ways. One way is through direct physical contact, like touching or kissing a person who has the infection. Another way is when an infectious microbe travels through the air after someone nearby sneezes or coughs.

Fatal Diseases : Diseases leading to failure or disaster.

Incurable Diseases : Diseases of a sick person not able to be cured.

The founder of Arya Samaj, Swami Dayananda Saraswati gave the motto "Go Back to Vedas" to propagate the true knowledge of Vedas.

The first written story that has come down to us is The Epic of Gilgamesh.

It is a mythologized account of a historical figure, Gilgamesh, a ruler of the Sumerian city-state of Uruk, believed to have ruled sometime between 2700-2500 BC.

The particles which makes upon an atom are called subatomic particles. Electrons, protons and Neutrons that makes an atom are called subatomic particles.

Whereas,

An ion is an atom or group of atoms in which the number of electrons is different from the number of protons.

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The freezing point of water and melting point is 0 °C or 32 °F. The temperature may be lower if supercooling occurs.

Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that can later be released to fuel the organisms activities.

Photosynthesis can be represented using a chemical equation.

The overall balanced equation is

              $$\begin{gathered} 6CO2 + 6H2O →Sunlight C6H12O6 + 6O2 \\ Source of Carbon & Oxygen + \\ Source of Electrons & Hydrogen + \\ Energy that drives Photosynthesis ----> \\ Sugar + Gas produced by splitting water. \end{gathered}$$

Where 

CO2 = carbon dioxide 

H2O = water

C6H12O6 = glucose 

O2 = oxygen.