Seeing Atoms in ActionMiddle SchoolLauren & Bobby

Objectives•Determine the behavior of atoms with

temperature (MS-PS1-3)•Visualize the movement of atoms•Demonstrate the different properties of

water•(MS-LS1-3)•Compare adhesion, cohesion, and

capillary action (MS-LS2-3)

Review: What is an Atom?•Smallest unit of an element•“If an apple was magnified to the size of

the Earth, then the atoms in the apple would be approximately the size of the original apple” (Feynman, 1995).

•Composed of protons, electrons, and neutrons

Temperature•Influences the speed atoms travel•As temperature increases, the speed of

atoms increases•As temperature decreases, the speed of

atoms decreases

TemperatureThink of a pot of boiling water

Question: What happens to the water when you turn up the heat on the stove? Why?

Image From Microsoft Clip Art

Solid What is a solid?

Rigid structure Atoms are close together Little movement

Atoms

Liquid•What is a liquid?

▫More movement of molecules▫Molecules are still close together, but can

slide▫Takes the shape of the container▫Definite volume

Image From Microsoft Clip Art

Gas•What is a gas?

▫Constant movement of molecules▫Takes space of entire container▫No definite volume▫No definite shape

Increasing Temperature (Heating)•Solid Liquid (Add heat)

▫Example: Melting butter in a saucepan•Liquid Gas (Add heat)

▫Example: Boiling water

http://www.abc.net.au/science/articles/2010/03/16/2840402.htm

Decreasing Temperature (Cooling)•Gas Liquid (Cooling)

▫Condensation on the mirror after a shower•Liquid Solid (Cooling)

▫Making Jell-O

Solid Liquid Gas

Heat decreases

Mini Lab

Image From Microsoft Clip Art

Capillary Action

Water•What does it mean to be adhesive?•What does it mean to be cohesive?

Adhesion of Water•The ability of water to stick to another

surface•An example of adhesion is when a water

droplet sticks to the leaf of a tree

Cohesion of water•Unique property that makes it possible for

water to stick to itself•Ex. Water droplet

Surface tension•Contractive tendency of the surface of a

liquid that allows it to resist an external force (science.yourdictionary.com).

Capillary Action•Is the ability of a liquid to flow in narrow

spaces without the assistance of, and in opposition to external forces like gravity. (science.yourdictionary.com)

•Both adhesion and cohesion allow for this to occur

•Ex. The xylem of wood plants is used to get water from the roots of the plant to the leaves. The way this is done is through capillary action.

Other examples of Capillary Action•Paint brush- to pick up paint•Cleaning up a spill with paper towels•Release tears from ducts of the eye