Counting by Weighing or Grouping Inquiry Lab Activity, Mole Concept Lab

This counting by weighing lab activity helps to solidify the mole concept for your students by having them measure things they can't see!

We can't see individual atoms or molecules, so in order to count them, we lump them together into larger groups of known quantity called "moles."

HOW IT WORKS:

First you establish how many objects are in a bundle. I like to call mine a "Reavy Bundle"

Then in beakers, jars, or containers were students can't count the number of objects inside, you put objects that are mostly identical in terms of mass. I like:

• cheerios
• dry beans
• coins
• paperclips
• crayons
• Molymod Hydrogen Atoms

Each of these containers has a label so students know how much mass to subtract for the container itself and how many "Bundles" (moles) are in the container.

For instance: If a jar contains 2 bundles of paperclips, and each bundle is 12, then there are 24 paperclips in the jar. If the mass minus the container is 48 g, then the mass of a single paperclip must be 2 g.

When this is done with multiple items (like paperclips and cheerios), students will come to realize that each of the bundles samples has only one thing in common. The quantity of the bundle. The same way 1 mole of helium has only one thing in common with 1 mole of carbon. It's the number of atoms!

This counting by weighing lab is a great way to allow students to grapple with the mole concept before getting into formula mass using the periodic table.

MATERIALS NEEDED:

• electronic balances
• beakers or containers
• paper, shopping bags, or aluminum foil to shield view of container's contents
• "bundles" of "atoms" which can be any type of object so long as they have "near identical mass" such as paperclips

FEATURES:

Students gain a deep understanding of the mole concept and its necessity in science while measuring things they can't see. This lab is very simple to set up, and is chemical free, making it super budget friendly! Students are given a very simple procedure and are expected to write a more detailed procedure as they work to determine the mass of just one item in each bundle.

WHAT'S INCLUDED?

• 2 versions of the lab, so you can use this as a quick demonstration or more lengthy inquiry lab
• teacher set up directions
• cards to label each station with the mass of the beaker and the shield
• "How to Write a Chemistry Lab Report" document so students are guided to write a thorough procedure and quality conclusion paragraph
• Differentiated lab conclusion option with sentence starters
• Answer Key
• Teacher Google Sheets calculator, to simplify your unique answer key

This product by Kelsey Reavy is copyrighted for single classroom only. This product may not be resold and can be copied for personal use within a classroom only. If you have questions, please email kelsey@kelseyreavy.com © Kelsey Reavy