The question asks for the popular name of J.J. Thomson's atomic model, which described electrons embedded in a sphere of positive charge. We need to recall the characteristics and common names of various atomic models.
Therefore, the correct option is C.
Correct Option: C) Plum pudding model — This model, proposed by J.J. Thomson, depicted the atom as a sphere of uniform positive charge with electrons (like "plums") embedded in it. Its popular name reflects this visual analogy.
The question asks for the principle that dictates the filling of atomic orbitals by electrons, starting from the lowest energy level. We need to identify the correct rule among the given options that describes this specific process.
Correct Option: D) The Aufbau principle describes the order in which electrons fill atomic orbitals, starting from the orbital of lowest energy. It is a fundamental rule for determining the electronic configuration of an atom.
The question asks about Heisenberg's uncertainty principle, a fundamental concept in quantum mechanics. This principle states that certain pairs of physical properties of a particle, like its position and momentum, cannot both be known with high precision simultaneously. The more precisely one property is measured, the less precisely the other can be known.
A) Position and momentum of an electron — This is the classic example of conjugate variables governed by Heisenberg's uncertainty principle. It is impossible to know both the exact position and the exact momentum of an electron simultaneously with absolute precision. If you try to measure one with high accuracy, the other becomes inherently uncertain.
The question asks about the relationship between the number of electrons and other atomic properties in a neutral atom. Understanding the basic structure of an atom and the definitions of atomic number, mass number, and neutrality is key to answering this question.
B) Atomic number — In a neutral atom, the number of positively charged protons is equal to the number of negatively charged electrons. The atomic number is defined as the number of protons in an atom. Hence, the number of electrons in a neutral atom is equal to its atomic number.
The question asks about the quantum number that determines the shape of an electron's orbital. We need to recall the roles of the four main quantum numbers in describing an electron's state in an atom.
Based on these definitions, the azimuthal quantum number is directly responsible for determining the shape of an electron's orbital.
D) Azimuthal (angular momentum) quantum number determines the shape of an electron's orbital. For example, \(l=0\) corresponds to an s-orbital (spherical shape), \(l=1\) to a p-orbital (dumbbell shape), and \(l=2\) to a d-orbital (more complex shapes).
The question asks to identify the term for electrons in the outermost shell of an atom that determine its chemical behavior. This is a fundamental concept in chemistry related to atomic structure and bonding.
Correct Option: C) Valence electrons are the electrons located in the outermost electron shell of an atom. These electrons are primarily responsible for an atom's chemical properties and its ability to form chemical bonds with other atoms. Their number determines whether an atom will lose, gain, or share electrons to achieve a stable electron configuration, typically an octet (eight electrons) or a duet (two electrons for hydrogen and helium).