Compléter Pre-Assessment CheckVersion en ligne Fill in the blanks with the correct answer. par Charlene Dinawanao 1 All substances are made up of matter and the fundamental unit of matter is the . The atom constitutes the smallest particle of a / an . The atom is made of a central nucleus containing ( positively - charged ) and ( with no charge ) . The ( negatively - charged with negligible mass ) revolve / s around the nucleus in different imaginary paths called orbitals or shells .