Memory Anchor:

• Super Challenge:

  Stretch:

  Challenge:

Key Questions:

1. What is an isotope?
   • An isotope is an atom of the same element with differing numbers of neutrons.
2. What do the individual tiles of the periodic table tell us?
   • The individual tiles of the periodic table tell us the chemical symbol, Mass number, Atomic (Proton) number
3. Calculate the number of protons, neutrons and electrons in an atom of Cobalt. Mass number = 59 and Atomic number = 27
   • The total number of subatomic Particles in cobalk are: Protons: 27 Electrons: 27 Neutrons: 32
4. How large are atoms? a) 1 × 10-6 m b) 1 × 10-8 m c) 1 × 10-10 m
   • The size of atoms are 1 × 10-10 m
5. Why does chlorine have a mass number of 35.5?
   • The relative atomic mass of an element is an average value that takes account of the abundance of the isotopes of the element. Chlorine exists as 75% Cl35 and 25% Cl37, an average of this is taken.
6. What is the relative atomic mass of bromine where there are two isotopes of Bromine, 50% Br-79 and 50% Br-81?
   • The relative atomic mass of bromine is 80, since (79 x 50) + (81 x 50) / 100 = 80.