atomic structure

what is the atomic number (Z)?

the number of protons in the nucleus of an atom

what is the mass number (A)?

the total number of protons and neutrons in the nucleus

what is an ion?

a positively or negatively charged atom or group of atoms

different isotopes of the same element…

react in the same way because they have the same electron configuration, may have small differences in physical properties because of a different in the nucleus

What is relative isotopic mass?

the mass of an isotope relative to 1/12th of the mass of an atom of carbon-12

what is relative atomic mass, Ar?

the weighted mean mass of an atom of an element relative to 1/12th of the mass of an atom of carbon-12

what does the weighted mean depends on?

percentage abundance of each isotope (found using mass spectrometer), relative isotopic mass of each isotope (accurate values obtained from m/z ratio)

What is the 1st ionisation energy?

Energy required to remove one electron from each atom in one mile of gaseous atoms of an element to form one mole of gaseous 1+ ions

What is the 2nd ionisation energy?

Energy required to remove one electron from each atom in one mole of gaseous 1+ ion of an element to form one mole of gaseous 2+ ions

What is the shielding effect?

Electrons in inner shells repel those in outer shells which reduces the nuclear attraction

What is an atomic orbital?

A region of space around the nucleus that can hold up to two electrons with opposite spin

What is a sub shell

A group of orbitals of the same type within a shell, with the same level of energy