Chemistry Topic 1 Definitions

Atomic Structure

What is a proton number

Number of protons in the nucleus of an atom and indicates the element’s position in the Periodic Table

What is a Nucleon number

Number of protons and neutrons found in the nucleus of an atom of an element

What is an Orbital

Volume of space in which there is a 95% chance of finding an electron

What are Isotopes

Atoms of the same element with the same number of protons, but different number of neutrons

What is The First Ionisation Energy

The enthalpy change required to remove one mole of electrons from one mole of gaseous atoms of the element to form one mole of gaseous unipositive cations

What is The Second Ionisation Energy

The enthalpy change required to remove one mole of electrons from one mole of gaseous univalent cations of the element to form one mole of gaseous dipositive cations