TLO 1 Atoms Flashcards
ELO 1.1 Describe protons and neutrons
Protons and neutrons located in a tight cluster called the nucleus. Protons give the nucleus its positive charge. Neutrons and protons are essentially equal in mass; together they make up the mass of the nucleus. Greater than 1800 times the size of an electron. Neutrons and protons each have a mass close to 1 amu.
ELO 1.1 Describe electrons
Electrons orbit nucleus in concentric orbits refer to as orbitals or shells. They are small and light and exhibit an electrical charge of -1 which equals in magnitude the charge of one proton. Electrons are bound to the nucleus by electrostatic attraction because opposite electrical charges attract.
ELO 1.1 Describe Bohr’s model of the hydrogen atom
The model shows an electron that has dropped from the 3rd shell to the 1st shell releasing energy in the process. The energy is released as a photon emission equal to h×v. h = Planck’s constant and v = frequency of the photon.
ELO 1.1 What is an Electron Volt (eV)?
The electron Volt is the unit for energy of subatomic particles. A proton’s eV value is +1 and an electron’s eV value is -1. A neutron has no charge.
ELO 2.1 Define a Nuclide
Nuclides are atoms that contain a unique combination of protons and neutrons.
ELO 2.1 Define an Isotope
An atom of an element that has a different number of neutrons than protons resulting in a different atomic mass number. While isotopes of a particular element have different atomic mass numbers, they have the same chemical characteristics which affects their radioactive stability.
ELO 2.1 Define Atomic Number and Neutron Number
The atomic number describes the number of protons in the atom’s nucleus and identifies the element. The neutron number denotes the number of neutrons in a nucleus.
ELO 2.1 Define Mass Number
The mass number of the atom = the total number of protons and neutrons in the nucleus. A = Z + N.
A = Mass Number
Z = Atomic Number (# of protons)
N = Neutron Number (# of neutrons)
ELO 1.3 Describe the 3 forces that act on particles within the nucleus and how they affect the stability of the nucleus.
Gravitational forces between any two objects that have mass creates a weak attractive force between all nucleons. Long distance force.
Electrostatic forces between charge particles create a strong repulsive force between like charged particles protons. Long distance force.
Nuclear force is a strong attractive force between all nucleons. This force is necessary to hold particles in the nucleus together as gravitational and electrostatic forces are much too weak. Extremely short distance force.
