Molecules in Motion!

The idea that everything is made of atoms and molecules that cannot be seen by the human eye can sometimes be daunting to middle school students. A scale that small is hard to conceptualize, and if that concept is tagged to the idea that those same atoms and molecules are moving and attracted to one another, you could have a classroom full of confused faces staring back at you.

This is the reason why I loved doing Sections 1.1 and 1.2 with my 7th grade classes using the website. I’m going to split this post into two parts in order to briefly highlight each section.

Section 1.1—Molecules Matter

Most of my students knew when coming into class that the three states of matter are solid, liquid, and gas, and so most of this lesson was spent focusing on how water molecules (and all liquid molecules) are moving and attracted to one another. In order to cover these concepts, middleschoolchemistry.com has students playing with water droplets on a sheet of wax paper with a popsicle stick. I am always surprised about how this simple lesson fascinates my 7th graders; they think it’s the greatest thing in the world. I usually prepare the index cards with wax paper beforehand, and it takes a bit of time. I would recommend either laminating index cards, or taping wax paper to something stronger like cardboard. It will last longer, and you can use it for multiple years.

Watching the water balloon pop in slow motion always received a lot of ‘Oohs’ and ‘Aahs’. I usually like to show other clips of slow-motion water balloons to drive the point home:

Section 1.2—Molecules in Motion

This is the first section in which a number of my science students encounter new material, or at least get more in-depth than what their prior knowledge provided them. Through the food coloring demonstration, students learn that heating water makes the molecules move faster, and my students enjoy watching the blue and yellow food coloring mix in both the hot and cold water without anyone stirring it. We have a one-to-one iPad program, so many of the students record the mixing of colors in order to review for assessments later. I accompany this lesson with a site called Nearpod, which is extremely helpful in assessing student learning and gaining data as proof of understanding.

The animations on the chemistry site are outstanding- it really helps middle school conceptualize big ideas, and the Extend portion of the lesson gets them thinking about thermal expansion already—even before we cover it in depth in sections 1.3 and 1.4. I enjoy taking it a step further with a video my colleague showed me—it’s corny and goofy, but covers the same concepts that I want my students to see. Furthermore, it’s in the form of song, and as you’ll soon see, I love creating science songs. The video is called Molecules in Motion, and the link to it is here:

After sections 1.1 and 1.2, I assign the 7th graders their first science homework assignment, which is to make a comic that expresses a major concept covered in the sections. These can be done on the iPad and printed out, or done by hand. I decorate my classroom with them, and it’s a chance for students to see that science can also be creative.

I’ve put a couple below for you to peruse, and I hope you have as much fun teaching these two lessons as I did!

Comic #1Comic #2

Michael teaches 7th and 8th grade science in Boston, Massachusetts.

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