Question

In nucleus of uranium the number of neutrons will be
$\left( {\text{A}} \right){\text{ }}92$
$\left( {\text{B}} \right){\text{ }}235$
$\left( {\text{C}} \right){\text{ }}143$
$\left( {\text{D}} \right)$ Different for different isotopes

Answer 1

Atom: It is defined as the smallest unit of ordinary matter that forms chemical elements.
The atom is composed of a nucleus and one or more electrons; electrons are bound to the nucleus.
Nucleus: It is a dense region that consists of protons and neutrons at the center of the atom.
Isotopes: Each of two or more forms of the same element that contain equal numbers of protons but numbers of neutrons is different in their nuclei.

Complete step by step answer:
Isotopes of Uranium atoms: Uranium has three isotopes Uranium- $238$, Uranium- $235$, Uranium-$234$. All these three isotopes of Uranium are radioactive. It is a naturally occurring radioactive element that has no stable isotope. Uranium-$238$ and Uranium-$235$ have long half-lives and these are found on the Earth’s crust. Uranium-$238$ is an alpha emitter, Uranium-$235$ is important for nuclear reactors and nuclear weapons.
Properties and use of Uranium:
Its slow radioactive decay generates a major heat source within the Earth; it is responsible for continental and convection drift.
Due to the high density of Uranium, it is used as counterweights of the aircraft control surface and radiation shielding.

Hence, the correct option is $\left( {\text{D}} \right)$.

Note:
Isotopes have the same physical properties but different chemical properties.
Isotopes are used to generate alpha radiation, beta radiation, and gamma radiation in nature.
Isotopes have the same electronic configuration, different density.
The nucleus is positively charged as it contains protons having positive charge and neutrons having zero charges.