Questions

Citric acid is present in tomatoes.

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...

The shape of two fingers shown up will be in 'V' and it represents in Roman letters, a number 5.

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. 

Indian anti-hunger activist Ankit Kawatra has honoured with the 2017 Queen’s Young Leaders award for his exceptional work in transforming the lives of others. Kawatra is among the 60 others from all 53 Commonwealth countries to be felicitated with the prestigious award by Queen Elizabeth (II) at a ceremony in Buckingham Palace in London on June 29, 2017. The honourees will also undergo a year-long mentoring and online learning by the University of Cambridge to build leadership capabilities and better their work towards the communities. He is the founder of Feeding India, a not-for profit organization that works towards solving problems of hunger, malnutrition and food wastage, mainly by redistributing extra food from restaurants, canteens, households, corporates etc. to help people in need.