Questions

Earth Hour is a people's movement inspiring individuals from more than 7000 cities across the globe to take a stand against climate change, making it the largest voluntary movement ever witnessed in history.

On 25 March 2017, Switch Off and Switch Onto Solar Energy

A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment. Such fact-supported theories are not "guesses" but reliable accounts of the real world. Scientific theories are not ever proved in the sense of being proved to be 100% correct.

Examples of some scientific theories are ::

Evolution, gravity, atomic theory, the germ theory of disease, relativity, quantum theory, electromagnetic theory, layered Earth theory, etc...

We know that, Elements in the same group of the periodic table have similar characteristics.

Here Magnesium and Strontium shared some similar properties because they both belong to the same group. Sr is the chemical symbol for strontium which is a group two element; it has atomic number of 38. 

When a muscle is contracted and relaxed some amount of heat is released as a by product. 

Citric acid is present in tomatoes.