The first one is the answer
isotopes of an atom have different number of neutrons . the number of protons are not different in isotopes of an atom
Allergies arise when a foreign material such as pollen, bee venom or pet dander responds to your immune system or a food that in most people does not cause a reaction. Substances known as antibodies are formed by your immune system.
Since an acidic salt solution is produced when a strong acid neutralizes a weak base, the pH of the salt solution formed when HCl is added to R2NH will be less than 7.
<h3>What is a neutralization reaction?</h3>
A neutralization reaction is the react ion between an acid and a base to form salt and water only.
Neutralization reactions can either produce a neutral solution, an acidic solution or an alkaline solution at equivalence point.
When a strong acid is added to a weak base, the pH of the salt solution formed will be less than 7.
Therefore, the pH of the salt solution formed when HCl is added to R2NH will be less than 7.
Learn more about pH at: brainly.com/question/940314
C. Cello playing music at a concert
Can you please tell me what the procedures are