Questions

A chemical reaction in which involves the absorption of heat from the environment is called a Endothermic reaction. 

Examples : Dissolving ammonium chloride in water, photosynthesis, melting ice cubes, mixing of potassium chloride with water,...

In the contrast, chemical reactions involving release of heat are known as exothermic reactions.

Examples : Combustion, coal is burnt, mix of CaO with water,...

Most stars are at main sequence point in their life cycles.

Laterite soils are a tropical soil and possess a great amount of iron and aluminum. Due to its high iron oxide content they look like rusty-red coloration.

A fingernail.

Spanish Armada

If an object moves with some velocity that means the magnitude and direction of the object changes i.e, the object moves with some acceleration. Hence, if the object moves with constant velocity, no change in direction and magnitude of speed i.e, no acceleration = 0 acceleration.