CLASSROOM CHEMISTRY

What is chemistry? What is matter? Chemistry is the study of matter. Matter is anything that takes up space, and has weight. Matter is made up of atoms and molecules

Matter:

All matter on earth exists in one of the following states: SOLID LIQUID GAS

WHAT IS THE DIFFERENCE BETWEEN SOLIDS, LIQUIDS AND GASES? The state a substance is in depends on the amount of kinetic energy that the particles have So what is Kinetic Energy? So what are Particles??

Energy POTENTIAL ENERGY KINETIC ENERGY “Stored energy” gravitational chemical (battery) elastic (spring) Energy in MOTION. The energy that an object possesses because it is in motion.

Particles: a generic term used to describe atoms and molecules So what are atoms and molecules? ATOMS: The smallest building block of matter Made up of NEUTRONS, PROTONS, and ELECTRONS MOLECULES: Two or more atoms

This is an atom of Oxygen: This is how Oxygen looks on the Periodic Table of Elements Electrons Nucleus (contains protons and neutrons) This is the atomic number of Oxygen. It shows that an atom of Oxygen has 8 protons Oxygen has 8 electrons and 8 protons (which are located in the nucleus) Elements are atoms with specific characteristics.

The Periodic Table:

Periodic Table About Me!

This is a Molecule of water REMEMBER! A molecule is two or more atoms Water’s chemical formula is H20 This means there are: 2 atoms of hydrogen, and 1 atom of oxygen ...Does that mean water is a chemical?

Talk! Is it true that we shouldn’t eat chemicals and ingredients we don’t recognize or can’t pronounce? Would you be alarmed if I said that as a treat we were going to drink a solution of CO2, C12H22O11, and H20 ?

A mixture is when particles of one substance are mixed with particles of another substance. Some things to know about mixtures: All kinds of matter can be mixed together, regardless of the state it is in (solids with solids, solids with liquids, solids with gases, etc) There are natural and man-made mixtures

TYPES OF MIXTURES/MIXTURE DEFINITIONS: Homogenous: When one substance is mixed in another so that it is uniformly dispersed throughout and you can’t see the separate parts. Example: Gatorade Heterogenous: When one substance is mixed with the other substance but you can still see the original components Example: pizza Solution: A special homogenous mixture formed when one substance is dissolved in another Example: salt and water

Solutions Terminology: Dissolving: A process where the particles of one substance become completely intermingled with the particles of another substance and remain that way indefinitely Solute: The substance being dissolved (usually the substance of smaller quantity) Solvent: The substance doing the dissolving (usually substance of larger quantity) EXAMPLE: When we dissolve sugar in water, the sugar is the solute and the water is the solvent

But first! When we have a solution (of sugar and water, for example) it is important to keep in mind that the sugar has not disappeared. We know this because if we drink the solution, it still tastes sweet. The sugar hasn’t disappeared, it has just dissolved.

Q: What do you do with a sick chemist? A: If you can't helium, and you can't curium, then you might as well barium. If the Silver Surfer and Iron Man team up, they’d be alloys.

Some ideas from last class: Sometimes we can’t tell if something is a mixture We can mix all kinds of matter together to get different mixtures There are some mixtures we can separate, and some we cannot

Some ideas to consider: A reversible change: Is when the substance can be brought back to its original form Changing H2O from a solid to a liquid Mixing pebbles and rocks Dissolving sugar in water A reversible change might change how something looks or feels, but it doesn’t create something new Examples: melting, freezing, boiling, dissolving

Some ideas to consider: An irreversible change: Is when the substance cannot be brought back to its original form. New materials are always formed Lighting a match Frying an egg! Examples: heating, mixing, burning

Chemical Changes or Reactions:

Change in colour or smell Formation of a precipitate *a precipitate is a solid that forms from two solutions being mixed together Taking in, or giving off of energy Bubbles