John-Hanson Machado

In December 2016, ACS Chemistry Ambassador John-Hanson Machado had the opportunity to give back to a public school near his hometown in southeastern Massachusetts.

Machado, a graduate student at George Washington University in Washington, D.C., led 130 fourth grade students – including his sister’s class – in a hands-on chemistry activity just before winter break.

He used Epsom salt and Ivory soap for the formation of a precipitate (soap scum). This activity is described in Inquiry in Action: Investigating Matter Through Inquiry, 3rd Edition produced by the ACS Division of Education.

Machado says labeling the ivory soap as “sodium stearate” and the epsom salt as magnesium sulfate made students feel more like chemists and contributed to the care they took in measurements - the reactants were now viewed by the students as chemicals rather than common household products.

Machado tweaked the instructions a bit, asking one group to add the hard water to the soapy water. This resulted in a much clearer precipitate formation than the suggested protocol. Other modifications included having the students’ stir rather than blow with a straw to form soapy water.

Looking ahead, Machado hopes that new resources are developed for the younger grade levels, such as Inquiry in Action tailored to Next Generation Science Standards. He also hopes to improve his skills in giving non- technical presentations to civilians or even 4th graders.

All in all, Machado says it was an enjoyable experience and he’s glad he had the opportunity to give back to a local community and promote the chemical enterprise through the ACS Chemistry Ambassadors Program.

John-Hanson Machado shared his enthusiasm for chemistry with fourth-grade students.
Credit: John-Hanson Machado

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