Activity 5: Density

1. Run the Build an Atom simulation http://phet.colorado.edu/en/simulation/build-an-atom and build a neutral lithium atom and a neutral boron atom. 

Neutral Boron Atom

Boron
Protons: 5
Neutrons: 6
Electrons: 5
Density: 2.08 g·cm⁻³

Neutral Lithium Atom

Lithium
Protons:3
Neutrons:3
Electrons:3
Density: 0.534 g·cm⁻³

2. Define density and the equation for density.

The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ (the lower case Greek letter rho). Mathematically, density is defined as mass divided by volume:

ρ is the density 

m is the mass

V is the volume

Density, Wikipedia, 11 July 2012, Web, 13 July 2012

3. Run the Density simulation http://phet.colorado.edu/en/simulation/density 

Teaching idea completed: Density -  Middle School Level 

Same Mass

Same Volume

Same Density

Mystery

5. Standards that could be met through these activities completed in Activity 5

Standard D: Physical Science

PROPERTIES OF EARTH MATERIALS
D.4.1 Understand that objects are made of more than one substance, by observing, describing and measuring the properties of earth materials, including properties of size, weight, shape, color, temperature, and the ability to react with other substances

STRUCTURE OF ATOMS AND MATTER
D.12.1 Describe* atomic structure and the properties of atoms, molecules, and matter during physical and chemical interactions*
D12.2 Explain* the forces that hold the atom together and illustrate* how nuclear interactions* change the atom
D.12.3 Explain* exchanges of energy* in chemical interactions* and exchange of mass and energy in atomic/nuclear reactions