Resources: Class presentation, handout and modelling materials to make a model of lithium (optional).
Handout: Introduce the idea of history in science and the role women play in discoveries. Use this to discuss the invisibility of women in science.
Practice calculating the protons, neutrons and electrons in an atom and isotope using information from the periodic table and apply this knowledge to new examples
What’s the difference between isotopes and ionisation? Read through the definition together and provide a brief description of charging a balloon with static electricity so that it makes your hair stand-up to reinforce the definition of an ion. Discuss what the atomic mass is and explain that when that changes and the atomic number remains the same, you have an isotope.
Use the handout to reinforce the lesson. Read through the first part and relate the context of women at that time not having the same status as men. Study the paragraphs regarding isotopes and ions. Ask students to work through the sheet and then disseminate the answers to the entire group to enable sharing.
Make a model of a lithium atom. Model the atom so that you can remove or add neutrons to present the different isotopes; lithium 6 and lithium 8.
Practice calculating using the periodic table for isotopes and for ions.
The visibility or invisibility of women scientists in the history of science – what conclusions can you draw from this?
Career Film: This is Dr Tim Gregory. Tim works as a Chemical Analyst for National Nuclear Laboratory.
Expert Film: This is Dr Tim Gregory. Tim works as a Chemical Analyst for National Nuclear Laboratory. Tim talks about how he uses isotopes and ionisation in his work.
Students follow the PowerPoint and make notes/answer questions
Use the handout to explore and discuss the role of women in the context of historical discoveries.
Practice applying knowledge of atomic mass number and proton number to work out the protons, neutrons and electrons in atoms and isotopes.
Challenge Task:
Ask students to explain how a potassium atom becomes a potassium ion.
Ask students to write a ½ equation to show this.
Repeat the above for an aluminium and fluorine atom.
Summarise the rule for working out the charge of an element from its position on the periodic table.
Complete the summative questions quiz at the end of the presentation.
Ask the students the following questions: Why does Cl have a mass of 35.5? How can an atom have half a proton? Challenge students to work out that it is an average.