Question

The atomic weight on an atom is due to:
A. Electrons and protons
B. Electron and neutron
C. Protons and neutrons
D. Electron, protons and neutrons

Answer 1

Atomic weight: Atomic weight is defined as average weight of the atomic mass of the natural isotopes of an element. It is also called a relatively atomic mass. The standard unit of atomic mass has been one twelfth mass of an atom of the isotope carbon-12.

Complete step by step answer: We will first describe the structure of atom:
Atoms are the smallest part, into which elements can be divided. Basic structure of an atom includes a tiny, relatively massive nucleus. Atoms consist of 3 particles: electron, proton and neutron. One Protons and one or more neutrons are present at the centre of the atom in the nucleus and outside the atomic structure one or more electrons present in the surrounding shell. According to the size of the electrons, protons and neutrons consist most of the volume of an atom.
Protons are positively charged and have mass $1.67 \times {10^{27}}$.
Neutrons have no charge and the mass of the neutron is equal to the protons.
Electrons are negatively charged and have mass $9.1 \times {10^{ - 31}}$ and are negligible in comparison to the mass of the nucleus.
The electronic configuration of an atom also helps to describe the arrangement of an electron distribution among the orbital shells and subshell and is also used to ionize an atom into cation and anion by compensating with loss or gain of electron in subsequent orbital.
So according to this theoretical concept of an atom the correct answer is (C) proton and neutrons.

Note: Atomic weight of an element provides various properties to the element. The weight of an atom can be changed with the loss or gain of electrons or protons from the atom. If there is gain of ions the weight increases and if there is loss then weight decreases.