Week 2
Density
Last week we learned about the origins and construction of Earth. This week we will learn more about its structure and how it works as a whole. We left off as the Earth was forming from the bombardment of material in the early Solar System. This constant bombardment caused incredible amounts of heat due to the friction of impact and the cumulative effect was a mostly liquid, molten Earth.
Day 1
The Earth must have been molten during formation for heavy elements like Fe and Ni to sink into the core and for lighter elements like Al and Si to float up toward the crust.
Density is the amount of stuff in a particular area
or
mass per unit of volume.
Atomic Structure all atoms are roughly the same diameter (volume) but all have different numbers of protons and neutrons (mass). The more mass an atom has the more dense it is. As rocks and dust accumulated on Earth from space and melted, the elements contained were free to migrate within the newly formed, liquid, molten planet. More dense materials sunk to the core and less dense materials floated to the surface.
States of Matter a particular element has a particular density (see above) and at the atomic level that cannot be changed. Above the atomic level density can be changed by moving the atoms closer to each other or further away from each other by changing temperature or pressure.
Density Changing the temperature or pressure of a material changes only one thing, the volume of the object. When an object is compressed its volume decreases. When an object is heated its volume increases. Whether an object sinks or floats is determined by the ratio of mass to volume.
Day 2
Density Concepts:
More dense sinks and less dense floats
More heat less dense and less heat more dense.
The higher the value of density the more dense it is. Ex. 10g/mL is more dense than 1g/mL.
Water is 1g/mL
Convection currents occur when material is heated making it less dense and float toward a cooler area where it cools and becomes more dense and sinks.
Imagine the planet as a gradient of heat and pressure. Both increase as you move toward the core. Imagine how this effects the density of material in these locations based on what you have learned.
Start from the 3 minute mark.
Day 3
Density in the mantle virtual lab. Find the materials in Google Classroom.
Day 4
The differential in heat and pressure that occur in the Earth's interior set up convection currents.
Debrief virtual lab activity from yesterday with a discussion on the connection between the lab today and convection currents.
Complete the in class density and convection lab (Lava Lamp).
Day 5
Density and Convection Study Guide
Solve for the missing variable given two of the three variables density, volume, and mass.
Recognize the units of density, mass, and volume.
Determine whether an object floats or sinks given the density of the object and the fluid that it is in.
Determine how liquids will layer in a container given their density or relative density given their position.
Know how changes in temperature and pressure influence the density of an object.
Determine the the relative density of solid, liquid, and gas of most substances and how they differ from water.
Know the relative density of Earth’s layers (crust, mantle, outer core, and inner core.)
Know three sources of the heat that is in the core of Earth.
Review
Quiz in Google Classroom