A solution is turning blue means, it is turning it's behavior to Basic from Acidic. Reagent D must be a Basic component so it is increasing the pH of the solution. As reaction does not depend on the phase of the component, it could be anything i.e., Solid, Liquid or gas.
Hope this helps!
DNA, which is found in chromosomes in the nucleus
In a nutshell, stars are mainly made of hygrogen, element 1.
over time, elements got more dense as they collided and cooled, leading to other gases, metals...
then they explode, which lead to all kinds of further complex elements.
The stuff that makes up the universe a lot of it is from exploding star stuff, and the Earth was built up upon these remains and the atoms that make up organisms even could originally be from stars.
The scientist that developed this model is J.J Thomson.
