The main use of litmus is to test whether a solution is acidic or basic. Blue litmus paper turns red under acidic conditions and red litmus paper turns blue under basic or alkaline conditions, with the color change occurring over the pH range 4.5–8.3 at 25 °C (77 °F).
Insertion of human genes into bacteria, also known as recombinant DNA technology, is used for the large scale production of human insulin, using bacteria as the insulin-producing machinery. The gene containing information for insulin production is inserted into the DNA of bacteria, which transcribe and translate it, and insulin is produced.
I believe the correct answer from the choices listed above is option D. Catalysts lower the activation energy of a chemical reaction. It <span>is a substance which speeds up a reaction, but is chemically unchanged at the end of the reaction. It provides another pathway for the reaction to occur.</span>
If we have a neutral atom, then it has the same number protons and neutrons.
The number protons and neutrons for neutral atom shows atomic number.
"A neutral atom has an atomic number of 20" means that atom has 20 protons (that give charge "+ 20" ) and 20 electrons (that give charge "-20").
Answer is 20 electrons.