[Anand]

AIDS(Acquired immunodeficiency syndrome) is a disease caused by HIV(Human Immunodeficiency Virus). It affects the body by weakening the immune system. Life expectancy is about 20 to 36 years less than that of a normal human. Hope it helps!😀

[Anand]

Also, the reason why electrons don’t fall into the nucleus because of positive attraction from the nucleus is because of quantum mechanics. Electrons can only receive/lose a minimum amount of energy(ground state).

[Anand]

Elements with the same no. of protons and electrons but a different number of neutrons are called isotopes. They are different because the isotopes have different masses.Also, some isotopes undergo radioactive decay faster than others because of imbalance is the number of protons and neutrons in the nucleus. Hope it helps!