Chemistry Review

Lesson Clarity:

What I will be learning.....

I will be reviewing some basic chemistry from matter, atoms, molecules

Why I will be learning this......

We are beginning to learn about cells, so we must begin by learning about the basic building blocks of cells....organic molecules

How I will know I learned this.....

I will be able to discuss what matter is, atoms, ions, and atomic bonds are.  I will be able to identify elements on the periodic table, their atomic number, weight, and element symbol.

CHEMISTRY REVIEW:

All of life is chemistry.  You are made up of about 30 trillion cells, and each of those cells are made of molecules from things you ate. We consume and digest molecules and then those molecules are broken down to release energy, or used by your body to build structures and substances that your body needs.  The walls of your cells require fats, your blood cells require iron, your muscles require protein, your hormones, enzymes, immune system......all require you to eat something and then add it you.  To understand cells we have to begin by understanding the basic building blocks of cells....macromolecules and nutrients.  To understand molecules we will need to review some chemistry.  

Consider the pictures below:

All of these pictures have something in common.

What do you think that is?

MATTER AND ENERGY:

All things are made of matter.  The only things that you experience not made of matter,  are energy. MATTER- is anything that takes up space and has mass.  Non-matter includes the light from a candle, the heat from a campfire, and the sound of a firetrucks siren. You cannot hold, taste, or smell these things. They are not types of matter, but forms of energy usually...there are a few other types of non-matter we can theorize about. Everything that exists can be classed as either a type of matter or a form of energy or non-matter. Energy- the capacity for doing work.  It can be potential, Kinetic, thermal, chemical, nuclear, and more. 

Examples of matter include:

1. the food you ate for lunch.

2. Your pen and notebook.

3. The air you are breathing.

4. Grass

5. the door

6. your uniform

Examples of Non-matter include:

1. Vacuum- empty space with nothing in it

2. Energy

3. Time

4. Rainbow

5. Gravity

6. Magnetism

8. Music

ATOMS AND ELEMENTS

All matter is made up of atoms and molecules.  Those atoms can each be classified as one of 118 known elements. An atom is the smallest unit of a chemical element. An element is a substance that cannot be further broken down by any chemical reaction. An element is an atom, or group of atoms, that has a specific number of protons in its nucleus.  Atoms are made up of three basic subatomic particles, electrons, protons and neutrons.  Electrons have a negative charge and orbit the atom in energy shells.  Protons have a positive charge and are in the nucleus, the middle of the atom.  Neutrons have no charge and are also in the nucleus.  The number of protons defines which element an atom belongs to.   An atom of an element will ALWAYS HAVE THE SAME NUMBER OF PROTONS, but they can have different numbers of neutrons.  An atom of an element with a different number of nuetrons than normal is called an ISOTOPE. 

A nuetral atom has the same number of electrons and protons. Atoms often interact with each other, losing or gaining electrons.  They never lose protons or nuetrons, only electrons. An Ion is an atom that has gained or lost electrons.  Anion is a negative ion which has gained electrons.  A Cation is an ion which is positive and has lost electrons.

 A greek philosopher, Democritus, theorized that there might be such tiny little pieces that made up matter, long before we knew there were atoms. 

He called them atomos.....that which can't be split.   Gold, tin , iron, copper, and mercury are elements and they have been known about for thousands of years but the first true scientific discovery of an element was by Hennig Brand who discovered Phospourus. As more and more elements were discovered scientists tried to organize them.  One brilliant man was able to create what we know as the PERIODIC TABLE, which organized elements into the patterns their properties formed.

  Demitri Mendeleyev organized elements into the periodic table according to their atomic number, 

valence electrons, and properties such as melting point.  It was such a good organization, he even predicted the discovery of some elements where he had empty spots in the table.  These elements were discovered after his death and his predictions were correct.

Element symbols for chemical elements normally consist of one or two letters from the modern or latin alphabet and are written with the first letter capitalised.  There are some hard ones to find, because they were named in latin, their abbreviation is from latin, but we call them by their modern name.  Lead is a good example of this. The latin name for lead is Plumbum.

Try to find five different elements and identify their atomic number, atomic weight, their element symbol and full name, and position in the periodic table.  This diagram is helpful. 

THE TWO TYPES OF MATTER

There are two types of matter, mixtures which can physically seperated. The other types of matter are pure substances, which include elements and compounds. 

Elements can not be broken down by a chemical or physical process, only nuclear fusion or fission.   An element can be asingle atom, or an element molecule, which is one or more atom of the same element bonded together. 

Compounds are two or more atoms of two or more elements bonded together. Compounds can be broken down or changed by chemical processes.  Compounds always combine in the same proportions.

The only way to change an element is through nuclear fission, which is the splitting of an atom into two or more smaller ones, with a different number of protons. Also nuclear fusion is the fusing of two or more smaller atoms into a larger atom with a different number of protons. Atom smashers, or particle accelerators, which produce nuclear reactions from colliding particles with atoms or other subatomic particles at close to light speed, creating new particles and radiation that tell scientists about the building blocks of matter.

BONDS BETWEEN ATOMS:

There are two basic types of bonds between atoms, ionic and covalent.

Ionic Bond- one atom loses an electron and another atom gains an electron- they remain together because opposites attract.  This is a more easily broken bond. 

Covalent Bond- two or more atoms share one or more electrons.  Up to three covalent bonds can be formed between atoms.  Covalent bonds are strong.