Atomic Structure — Set 3
Chemistry · परमाणु संरचना · Questions 21–30 of 50
What is the shape of an 's' orbital?
Correct Answer: A. Spherical
The correct answer is 'Spherical'. The 's' orbital is mathematically represented as a sphere centered on the nucleus. It is the only orbital type present in the first energy level (n=1). The probability of finding an electron is the same in all directions from the center.
Which fundamental force holds the protons and neutrons together in the nucleus?
Correct Answer: C. Strong nuclear force
The strong nuclear force is the most powerful force in nature but acts over very short distances. It overcomes the electrostatic repulsion between positively charged protons. Without this force, the nucleus would instantly fly apart.
An atom that has gained or lost electrons and carries a charge is called a/an?
Correct Answer: A. Ion
Ions are formed when the balance between protons and electrons is disrupted. Loss of electrons creates a positive cation, while gain creates a negative anion. This process is fundamental to the formation of ionic chemical bonds.
What is the maximum number of electrons that can fit into a 'p' subshell?
Correct Answer: C. 6
A 'p' subshell contains three individual orbitals. Each orbital can hold two electrons, leading to a total capacity of six. These orbitals are oriented along the x, y, and z axes.
Which model of the atom is often referred to as the 'Planetary Model'?
Correct Answer: C. Bohr's Model
Bohr's model depicts electrons moving in fixed circular paths around the nucleus, similar to planets orbiting the Sun. It successfully explained the line spectrum of hydrogen. However, it was later replaced by more complex quantum models.
What is the mass of a neutron relative to an atomic mass unit (amu)?
Correct Answer: B. 1
The mass of a neutron is approximately 1.0087 amu, which is nearly equal to 1. This is very close to the mass of a proton. Together, they define the integer value of an atom's mass number.
Which element has only one proton and no neutrons in its most common isotope?
Correct Answer: B. Hydrogen
The most abundant isotope of Hydrogen, called Protium, lacks a neutron entirely. It consists simply of one proton and one electron. Other isotopes like Deuterium and Tritium do contain neutrons.
The arrangement of electrons in the various shells of an atom is known as?
Correct Answer: A. Electronic configuration
Electronic configuration describes how electrons are distributed among the available orbitals. It follows specific rules like the Aufbau principle and Hund's rule. This arrangement dictates the chemical behavior of the element.
Which type of radiation has the highest penetrating power?
Correct Answer: C. Gamma rays
Gamma rays are high-energy electromagnetic waves with no mass or charge. Because they lack charge, they do not interact as easily with matter as alpha or beta particles. They require thick lead or concrete shielding to be stopped.
What is the value of the charge on a single electron?
Correct Answer: B. -1.6 × 10^-19 Coulombs
The correct answer is '-1.6 × 10^-19 Coulombs'. The charge of an electron is negative and was first measured accurately by Robert Millikan. It is considered the elementary unit of negative charge. Protons carry an equal magnitude but positive charge.