class 11 ncert chemistry chapter structure of atom Flashcards
What is the basic unit of matter?
Atom
True or False: Atoms can be divided into smaller particles.
True
What are the three main subatomic particles of an atom?
Protons, Neutrons, and Electrons
Fill in the blank: The nucleus of an atom contains ____ and ____.
Protons and Neutrons
What is the charge of a proton?
Positive
What is the charge of an electron?
Negative
What is the mass of a neutron compared to a proton?
Approximately equal
Which subatomic particle determines the chemical properties of an element?
Electron
What is the atomic number of an element?
The number of protons in its nucleus
How do you calculate the mass number of an atom?
Add the number of protons and neutrons
True or False: Isotopes of an element have the same number of protons but different numbers of neutrons.
True
What is an ion?
An atom or molecule that has a net electric charge due to the loss or gain of one or more electrons
What is the difference between a cation and an anion?
Cation is positively charged, Anion is negatively charged
Which model of the atom proposed that electrons move in fixed orbits around the nucleus?
Bohr model
What is the principle of uncertainty in quantum mechanics?
It is impossible to know both the position and momentum of an electron simultaneously.
Fill in the blank: The region around the nucleus where electrons are likely to be found is called an ____.
Orbital
What is the maximum number of electrons that can occupy an orbital?
Two
What are the four types of orbitals?
s, p, d, and f
What does the quantum number ‘n’ represent?
The principal quantum number, indicating the energy level of an electron
True or False: Electrons fill orbitals in order of increasing energy.
True
What is the Pauli Exclusion Principle?
No two electrons in an atom can have the same set of four quantum numbers.
What is Hund’s Rule?
Every orbital in a subshell is singly occupied before any orbital is doubly occupied.
What is the significance of the electron configuration of an atom?
It determines the atom’s chemical properties and reactivity.
What does the term ‘valence electrons’ refer to?
Electrons in the outermost shell of an atom
What is an atomic orbital?
A mathematical function that describes the wave-like behavior of an electron in an atom.
Fill in the blank: The first energy level can hold a maximum of ____ electrons.
2
