04.20.2020 - Science Notes -

04.20.2020 - Science Notes - Left side of notebook - 

Sixth grade:  tie-ins with social studies and what we’ve done in science.

As always, define any terms that are CAPITALIZED with which you are unfamiliar. 

1. Current Events:  CNN 10 - (link). https://www.cnn.com/cnn10
1. Two notes on Corona and social distancing.

II.  Today’s notes: A bit more on Oxygen and the ROCK CYCLE:  A little more background on what is, actually, cycling and we touch on some basics on CHEMISTRY.  You’ll get into chemistry in much more detail in seventh and eighth grade. There are a few basics we must know so that we understand a bot more about how DNA works and how we know what we know! 

III.  Think about your social studies classes and how you’ve studied ancient Egypt this year.

A.  One of the things you often discussed in social studies / history was the age of artifacts found in Egypt.

1.  One way we can determine the age of rocks or some FOSSILS, is by checking out what layer they are in compared with other layers of rock.

a). THE LAW OF SUPERPOSITION: It’s very important in geology and archeology. It says that, generally, the oldest layers of rock are on Botton and the youngest layers are on top.

B.  There is another, important, way we determine age of fossils and artifacts. This relates to some things we’ve learned, so far, in science. 

1.  In history class you read about CARBON 14 dating. Today’s notes are a brief look at what that is and how it relates to the rock cycle.

IV.  Look back on you notes (please) about ELEMENTS. Review and remember that, fourteen billion years ago - after the BIG BANG - there was only Hydrogen. Stars made all the heavier elements. 

A.  All the elements are listed on that big chart called the PERIODIC TABLE.

V.  Some of those bigger, heavier elements end up inside living things like us! 

A.  Look back PHOTOSYNTHESIS:  ELEMENTS can “stick” together to form different kinds of MOLECULES.  Photosynthesis - like the plankton and plants we’ve studied - rearrange CARBON DIOXIDE and WATER to make SUGAR and OXYGEN.

VI.  OK … Here’s the “new stuff.”  Some of those bigger elements (By “bigger elements” we mean anything bigger than HYDROGEN on that PERIODIC TABLE … sometimes they, naturally, “fall apart.”

VII.  A kind of CARBON - called “CARBON-14” - does this. It breaks apart. When it does, it releases RADIATION.

VIII. The big, heavy ELEMENTS that are inside Earth, naturally break apart over a very long time. As they do this, they release HEAT, helping keep the inside of Earth very, very hot! (The core of Earth is hotter than the surface of our sun!)

IX.  In our history class, we can tell how old some artifacts and fossils are by doing tests to see how much Carbon 14 is in them! It’s pretty accurate.

A.  Carbon-14 dating doesn’t work on things that are more than, about, 50,000 years old.