4.structure of atom Flashcards
Which aspect of Dalton’s atomic theory was proven incorrect by the discovery of electrons and protons?
Atoms are indivisible and indestructible
Who was the first scientist to propose a model for the structure of an atom?
J.J. Thomson
According to J.J. Thomson’s model, what analogy did he use to describe the atom’s structure?
(B) Christmas pudding
(C) Watermelon seeds
Question: What are alpha (α) particles?
Doubly-charged helium ions
According to Thomson’s atomic model, what is the relationship between positive and negative charges in an atom?
Both charges are equal in magnitude
What was the primary objective of Rutherford’s gold foil experiment?
To understand how electrons are arranged within an atom
Rutherford concluded that the positive charge in an atom is
Concentrated in a small region called the nucleus
Rutherford’s nuclear model of the atom proposed that
Electrons revolve around the nucleus in circular paths
Question: What was a major drawback of Rutherford’s atomic model?
It could not explain the stability of the atom
Question: According to Bohr’s model, what happens to electrons when they revolve in discrete orbits?
(A) They radiate energy continuously
(B) They do not radiate energy
(C) They lose mass
(D) They merge with the nucleus
They do not radiate energy
Which scientist proposed the concept of discrete orbits in the atom?
Neils Bohr
Rutherford is known as the “Father” of which field
Nuclear Physics
The energy levels in an atom are represented by which letters according to Bohr’s model?
K, L, M, N
Who discovered the neutron
J. Chadwick
Neutrons are present in the nucleus of all atoms except:
(A) Helium
(B) Carbon
(C) Hydrogen
(D) Oxygen
(C) Hydrogen
