Atomic Structure Flashcards
Nucleons
Nucleons are the sub-atomic particles that exist in the nucleus of atoms (protons & neutrons).
What holds protons and neutrons in the nucleus
The strong nuclear force holds together protons & neutrons in the nucleus
Electrostatic forces of attraction
Electrostatic forces of attraction exist between any positive and negative particles.
Isotopes
Isotopes are atoms of the same element with different numbers of neutrons. (same numbers of protons and electrons)
Relative atomic mass
Relative atomic mass (Ar) is the average mass of an atom of an element (taking into account the relative abundances of isotopes) compared to one twelfth of the mass of one atom of carbon-12
Relative isotopic mass
Relative isotopic mass is the mass of an atom of an isotope compared to one twelfth of the mass of one atom of carbon-12.
Atomic number
Atomic number (Z) is the number of protons in the nucleus of an atom of that element
What is A
A = mass number (no. of protons + neutrons in the nucleus)
What is a species
A species in chemistry is “a substance composed of chemically identical entities”
Relative molecular mass
Relative molecular mass (Mr) of a compound is the sum of the relative atomic masses of all the atoms in a molecule compared to one twelfth of the mass of one atom of carbon-12.
Relative formula mass
Relative formula mass (Mr) of an ionic compound is the sum of the relative atomic masses of all the atoms in the formula compared to one twelfth of the mass of one atom of carbon-12.
Main shell/quantum shell
A main shell or quantum shell is made up of sub-shells containing orbitals, where electrons are found.
Orbital
An orbital is a region of space in an atom containing up to two electrons with opposite spins.
Sub-shell
A sub-shell is one or more orbitals in the same shell which have the same energy levels.
s-block element
An s-block element has its highest energy electron in an s orbital