Chemistry Workbook Sample

Atomic number: the number of protons in the nucleus of an atom

Mass number: the total number of protons and neutrons in the nucleus of an atom

Isotopes: atoms with the same atomic number but different mass numbers or atoms with the same number of protons but different numbers of neutrons

Relative isotopic mass: the ratio of the mass of one atom of that isotope to 1/12th of the mass of one atom of carbon-12

Relative atomic mass: the ratio of the average mass of an atom to 1/12th of the mass of one atom of carbon-12

Relative molecular mass: the ratio of the average mass of a molecule (or formula unit) to 1/12th of the mass of carbon-12

Exam Style Questions - Atomic Structure

1. (a) Complete the table below to show the relative masses and charges of a proton, a neutron and an electron. Relative mass Relative charge Proton Electron Neutron

(b) Define the terms mass number and atomic number of an atom. Mass number....................................................................................................... Atomic number..................................................................................................... (c) Give the symbol, including the mass number and the atomic number, for the atom which has 3 fewer neutrons and 2 fewer protons than N. ..............................................................................................................................

(d) Define the term relative atomic mass of an element. .............................................................................................................................. .............................................................................................................................