To get: Chromebook- Log into Classroom To get out: Yellow Packet- Turn to pg 5- Introduction to chemistry To Turn In: Observing Living Organisms Lab (safety contract, info sheet) Homework: Read pg 11-12 (underline/highlight as you read and answer questions 1-8)

CHEMISTRY!?!!

Chemical Terms- Pg 5 Matter- anything that occupies and has The “stuff” of the universe All chemicals are matter just like all matter is basically chemical Space Mass

What makes up Matter? Atoms! Atom- The smallest possible of an element that still has the properties of that element. Made of 3 particles: Proton- A subatomic particle in the nucleus with a single positive charge Neutron- A subatomic particle in the nucleus with a neutral charge Electron- A subatomic particle that quickly moves around the nucleus with a single negative charge little mass. unit

**The proton and neutron together form the (atomic) nucleus.

Chemical Terms Element- a pure substance made of the same types of atoms that cannot be broken down into other substances by chemical means. Compound- a substance containing two or more elements that are chemically combined A great example is WATER Water is made of 2 Hydrogen atoms and 1 Oxygen atom (H2O)

Every element has a symbol containing 1 or 2 letters Ex: Carbon = _________ Sodium= ________ Hydrogen= _________ Chlorine= _______ Oxygen = ________ Calcium= ________ Nitrogen= _________ Phosphorus= ________ Use the chart to fill in the symbols for each element.

Atomic Number: The # of in the nucleus— different for each element. protons

In a neutral uncharged atom, the # of protons = # of electrons What is the charge on an atom with: 8 protons and 10 electrons? -2

What is the charge on an atom with 4 protons and 2 electrons? +2

Quick Review- Quiz on Google Classroom What is the smallest unit of an element? Where are Protons found? What is the charge of a proton? Where are Electrons found? What is the charge of an electron? What is the charge of an atom that has 5 protons and 6 electrons?

Electrons are arranged in energy levels (also called Orbitals or Electron Shells) The number of Valence Electrons, electrons in the outer electron shell, determines how reactive an element is. Atoms are most reactive when the outer shell is partially full (Atoms "want" to have a full outer shell!)

# of Electrons each energy level can hold: 1st Energy Level: 2 Electrons 2nd Energy Level: 8 Electrons 3rd Energy Level: 8 Electrons

Drawing a Bohr Model Oxygen: Atomic #8 # Valence e-= + Vacanices= 6 2

Draw a Bohr model of Magnesium Atomic # 12 # Valence e-= + Vacanices= 2 6

Chemical Bonding Atoms interact such that they all try to have 8 electrons in outermost orbit (energy level) The attractive forces between atoms in a compound are chemical bonds 11

Chemical Bonding Vocab: Molecule: A particle with 2 or more atoms bonded together Compound: Molecule with at least 2 different elements. They can have very different properties from the elements that make them up.

An example:  Chlorine is a greenish gas while sodium is a soft, shiny metal.  When the two are combined, white sodium chloride (table salt) is made NaCl

Chemical Bonding Covalent Bonds - Two atoms share one or more pairs of electrons Each ends up with 8 electrons in its outermost energy level (at least part of the time) 11

Draw a Covalent Bond Hydrogen Hydrogen + H H

Chemical Bonding Ionic Bonds - One atom loses electrons; the other gains electrons Ions: any atom/molecule with Charge (positive or negative) 11

Chemical Bonding Atom that loses electrons has a net positive charge Atom that gains electrons has a net negative charge Unlike charges attract An ionic bond is then formed from the attraction between the positive charge and negative charge 11

Sodium Chloride (NaCl) Draw an Ionic Bond: Sodium Chloride (NaCl) Sodium (atomic number 11) Chlorine (atomic number 17)