a rock, a penny, a butter knife (not plastic), a glass jar, and a journal
a rock, a penny, a butter knife, and a glass jar on a table.
a hypothesis about which items are harder than your rock and which are
Record your hypothesis in a journal.
test the hardness of your rock, try to scratch a penny, a knife, and a
glass jar with your rock.
your journal, record what items your rock scratched and what items it did
try to scratch your rock with your fingernail, a penny, and a knife.
the results in your journal.
Use the data you collected during the scratch test, to make a conclusion
about what items are harder than your rock and which items and softer.