Andres Robotics and Science
  • 1. Wheel Whacker
  • 2. Power Roller
  • 3. Brick Armor
  • 3. Wood Armor
  • Iron Man Ideas
    • 1. Basics & Beyond
    • 2. Joust
    • Football Derby ymxb
    • Rube Goldberg
  • wrestling

3 (e.a.) Element, Compounds and Mixtures

Picture
In this video we will show the difference between elements, compounds and mixtures using Legos.  The smallest unit of a substance is an atom.  One lego brick represents one atom that cannot be broken down.  Also there are many types of atoms which are all listed on the periodic table of elements.  Elements consists of only one kind of atom.   78% of Earth’s atmosphere is mostly made of the element N for nitrogen and 21% is made of O for Oxygen.    Both nitrogen and oxygen exist as elements in our air.  Hydrogen atoms and carbons atoms in our atmosphere but they usually bond with other atoms to form compound. 

The nitrogen in our atmosphere exists as a molecule N2.  Nitrogen Molecules form when two nitrogen atoms bond.  A nitrogen molecule is still considered an element because it is made of the same kinds of atoms.  The Oxygen molecules we breathe is O2.  Your blood carries O2 through the body.  There are only seven elements that can exist as molecules they are H2, O2, N2, F2, I2, Cl2, Br2.  The elements in our atmosphere will be written as N2 and O2. 

Elements cannot be broken down into a simpler type of matter by either physical or chemical means, and elements can exist as either atoms (e.g. carbon) or molecules (e.g., nitrogen and oxygen).

Compounds consists of atoms of two or more different elements bound together like two hydrogens chemically bond to one oxygen.  Water is a compound found in our atmosphere at 1-4 % depending on the humidity.  Distilled water in a jug is a pure substance because it only contains water molecules.   Pure water is a compound however tap water is not pure.

Carbon Dioxide is found in our atmosphere at less than 1 %, and as a greenhouse gas.  Greenhouse gasses trap the heat from the sun.  Carbon dioxide is a compound because it is made of carbon atoms and oxygen atoms.  Carbon dioxide can be broken down by photosynthesis which is a chemical reaction because it produces new substances like oxygen.  Dry ice is pure carbon dioxide making it a pure substance.  Compound have specific rations, for example H2O is 2:1 –hydrogen to oxygen and CO2 is 1:2 – carbon to oxygen.

Compounds can be broken down into a simpler type of matter (elements) by chemical means (but not by physical means).  Compounds have properties that are different from its component elements, and always contains the same ratio of its component atoms.

A mixture consists of two or more different elements and/or compounds physically intermingled.    They are in the same container but not chemically bonded.  Our atmosphere is a mixture elements (like nitrogen and oxygen) and compounds like carbon dioxide and water. This means that they are in the same place but are not chemically combined but are instead mixed physically.  A mixture can be separated into its components by physical means, and often retains many of the properties of its components.