15.2: The Bohr Model of Atomic Structure

Describe the properties of an atom.

15.2.A.1 Atoms have internal structure.

• 15.2.A.1.i Atoms consist of a small positively charged nucleus surrounded by one or more electrons.

• 15.2.A.1.ii The nucleus of an atom is made up of protons and neutrons.

15.2.A.2 Each atomic element has a unique number of protons.

• 15.2.A.2.i The number and arrangements of electrons affects how atoms interact.

• 15.2.A.2.ii The total number of neutrons and protons identifies the isotope of an element.

• 15.2.A.2.iii The mass of an atom is dominated by the total mass of the protons and neutrons in the nucleus.

15.2.A.3 The Bohr model of the atom is based on classical physics and was the historical representation of the atom that led to the description of the hydrogen atom in terms of discrete energy states.

• Within the Bohr model of the atom, electrons are modeled as moving around the nucleus in circular orbits determined by the electron’s charge, mass, and the electric force between the electron and the nucleus.

• The standing wave model of electrons accounts for the existence of specific allowed energy states of an electron in an atom as the electron orbit circumference must be an integer multiple of the electron’s de Broglie wavelength.

15.2.A.5.ii  The standing wave model of electrons accounts for the existence of specific allowed energy states of an electron in an atom as the electron orbit circumference must be an integer multiple of the electron’s de Broglie wavelength.