Agenda Vocabulary Review Game Notes: Composition of Matter What is matter? What information can we learn about chemicals from the periodic table? Vocabulary Review Game Notes: Composition of Matter Complete Periodic Table interactive worksheet & go over Notes: Bonding Bonding & Chemical Formula worksheet

Vocabulary Set #1 Matter- anything that has mass and volume Atom- smallest unit of an element that retains properties of the element Ion- charged particle Proton – subatomic particle with a positive charge; located within the nucleus of an atom Neutron- subatomic particle with a neutral charge; located within nucleus of an atom Electron- subatomic particle with a negative charge Covalent bond-bond formed when atoms share one or more pairs of electrons Ionic bond- bond formed when atoms transfer electrons from one atom to another

Molecule- group of atoms held together by chemical forces Element-substance that can not be broken down chemically Compound- substance made of atoms of two or more different elements Isotope- atoms of the same element with different number of neutrons Atomic Number- number of protons in an atom Mass Number- sum of protons and neutrons in the nucleus of an atom Enzyme- protein that speeds up metabolic reactions within organisms by reducing the activation energy required for chemical reactions

What in the world is matter?

Matter is… A. Anything that moves B. Anything that has mass and volume C. Something that cries.

B. Anything that Has mass and volume!

types The Of matter are…

Liquids Solids Gases Plasma

Structure of Matter Protons Positive charge Make up nucleus of atom All matter is made of atoms which contain Protons Positive charge Make up nucleus of atom Atomic number Neutrons Neutral Subtract atomic number from mass number Mass number = Neutrons + Protons

Electrons Negative charge Travel around nucleus within electron cloud 1st energy level-holds 2 2nd energy level- holds 8 3rd energy level-holds 18 If stable atom: # of protons=# of electrons

Information We Can Gain From Periodic Table Name Atomic Number The number of protons in an atom defines what element it is.  The number of protons in an atom also determines the chemical behavior of the element. If the atom is stable the atomic number also tells you the number of electrons Symbol The atomic symbol is one or two letters chosen to represent an element ("H" for "hydrogen”)  These symbols are used internationally.   Atomic Mass The average mass of an element and its isotopes in atomic mass units ("amu").  The number of neutrons for an element can be found by subtracting the number of protons (atomic number) from the atomic mass.  Atomic mass

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Chemical Bonds Remember most atoms are not stable in their natural state they tend to react with other atoms in different ways to become more stable. Atoms attempt to acquire an outer orbital with eight electrons through chemical reactions –Octet Rule Hydrogen and helium attempt to acquire an outer orbital with two electrons through chemical reactions Chemical bonds are the attractive forces between valence electrons that hold them together.

NA – 11 electrons 2 electrons – 1st shell 8 electrons – 2nd shell 1 electron – 3rd shell (valence electron

What is a compound? Compounds are made up of atoms of two or more elements in fixed proportions Compounds can contain different types of bonds. If atoms are sharing electrons, then the bond between them is covalent. If an atom gives up an electron to another atom, then they have an ionic bond.

Covalent Bonds Form when two atoms share one or more pairs of electrons

Ionic Bonds Ionic bonding occurs when one atom transfers an electron to another atom The opposite charges forms an electrostatic attraction between the ions Form between a metal on the left of the table and a nonmetal on the right side of the table. Cation looses electrons so it is oxidized. Anion gains electrons so it is reduced.

Other types of Attractions Hydrogen Bonds Occur between two hydrogen atoms that are already covalently bonded to different atoms. This is a weaker bond than a covalent bond Van Der Waals bonds short range attractive forces between chemical groups in contact. Caused by slight charge displacements.

Chemical Formulas Tells you what kind of atoms are in the compound Tells you the number of atoms of each type of element Are determined by the number of valence electrons, since these are the electrons that participate in bonding

Chemical Formulas How many valence electrons does hydrogen have? How many valence electrons does oxygen have? How many hydrogens are needed to fill oxygen’s shell? What is the chemical formula for water? How many hydrogen are there in one water molecule? How many oxygen are in one water molecule How many hydrogen are in three water molecules? 3 H2O

Criss-Cross Method Ionic compounds must have a net ionic charge of zero (neutral) Use crisscross method to write formulas The charge superscript becomes the subscript of the opposite ion indicating the # of ions

Example Barium bromide: Ba2+ Br-1 Barium loses 2 e- to become 2+ Bromide gains 1 e- to become 1- Criss cross superscripts to become subscripts – do not need to record 1 becomes BaBr2

EXAMPLES Aluminum oxide Al3+ O2- becomes Al2O3 Aluminum will loss 3 e- Oxygen will gain 2 e- Criss cross superscripts Practice…practice…practice Your turn….

Complete Bonding & Chemical Formula worksheet and discuss Homework: Counting Atoms worksheet Section 2-1 Review