ELEMENTS AND THE PERIODIC TABLE Chapter 5.5 – Day 2

Keep in mind that the atomic number is always lower than the atomic mass (weight)

ELEMENTS AND ATOMIC STRUCTURE The Bohr-Rutherford model of the atom suggests that atoms are composed of three types of subatomic particles: protons neutrons electrons

Bohr-Rutherford model 2, 8, 5 This is electron configuration Bohr-Rutherford Model Notice that the number of protons (P) and number of neutrons (N) goes in the center Remember the dots represent electrons (E)

PROTONS Are heavy positively charged particles that are found in a dense positive core of the atom called the nucleus The number of protons in an atom is equal to the element’s atomic number

NEUTRONS Are neutral particles that have about the same mass as protons and are also found in the nucleus.

ELECTRONS Are negatively charged particles with almost no mass that “orbit” the nucleus at different energy levels, also called orbitals or shells. The number of electrons in an atom equals the number of protons, therefore the atoms charge is neutral.

HANDOUT – 20 MINUTES Complete the handout by reading pages 185-186. Work with a partner if you like.

Same as Atomic Number Same as Atomic Number Protons Nucleus + ive Electrons Shells - ive Neutrons Nucleus neutral Same as Atomic Number Mass Number - Atomic Number Same as Atomic Number Neutral Electrons 2, 8, 8

IONS An ion (charged atom) in which the number of electrons is different from the number of protons. The IONIC CHARGE is the numerical value of the electric charge with a plus or minus sign. Give Handout to show examples.

HOMEWORK QUESTIONS PAGE 187: 4,5,6abc Ion Worksheet Quiz tomorrow on Chapter 5.1 and 5.5