Question of the day EOC PREP Sept 18 Which element is most important to composition of organic life? A. Hydrogen B. Silicon C. Carbon D. Oxygen JUSTIFY YOUR ANSWER… EXPLAIN WHY YOU CHOSE YOUR ANSWER!

AGENDA Sept 18 Learning Objective: 1. QotD 2. Complete the Pre-Assessment Activity 3. Introduce Chapter Closing Thoughts and Homework

Chapter 2 Introduction to Chemistry

What is Matter? matter: anything that has mass and takes up space physical properties: characteristic of matter that can be observed and measured examples are color, odor, shape, texture, taste, and hardness chemical properties: describes a substance’s ability to change into another new substance due to chemical change Occurs in a chemical reaction

Phases of Matter phases: physical property of matter that describes a different state of the same substance four phases of matter solidliquidgasplasma change from one phase to another is a physical change

2-1: The Nature of Matter atom: the basic unit of matter nucleus: center of the atom makes up 99.9% of the atom’s mass contains three subatomic particles: In the nucleus: Protons (+) and Neutrons (n) proton and neutron are nearly equal in mass Outside nucleus in energy levels: Electrons (-) have a mass 1840 times less than the proton and neutron

Atomic and Mass Number atomic number: number of protons in the nucleus of an atom identifies an atom mass number: the total number of protons and neutrons in the nucleus of an atom Mass of electrons are incredibly small.

Question of the day Sept 19 Which of the following is not a compound? A. CO B. Ti C. NaCl D. HCl

AGENDA Sept 19 Learning Objective: Compare and contrast the differences between elements and compounds. 1. QotD 2. Elements, Compounds, and Chemical Bonding 3. Closing Thoughts and Homework

Elements element: a substance which consists entirely of one type of atom How many elements are known to exist? isotope: an atom of the same element which has the same number of protons different numbers of neutrons

Radioactive Isotopes unstable nuclei break down releasing matter and radiation energy have many practical uses such as: tracers to study living organisms diagnose and treat diseases sterilize foods measure the ages of certain rocks

Chemical Compounds elements combine to form substances consisting of two or more different atoms in definite proportions

Interactions of Matter Chemical bonding forms compounds. electron energy levels 1 st level: 2 electrons 2 nd level: 8 electrons 3 rd level: 8 electrons If the Valence shell (outermost energy level) is full the atom is stable CONCEPT CHECK  Oxygen has 8 protons

Electron Shells Electrons surround the nucleus of an atom in electron shells or orbitals. The valence shell is the outermost shell. These electrons want to react making the atom stable.

AGENDA Sept 22 Learning Objective: Build chemical compounds to investigate bonding between atoms. 1. Chemical Reactions 2. Chemical Compounds Lab 3. Homework – Complete Lab Packet Questions 4. QUIZ TOMORROW – SECTION 2-1

Ionic Bond a bond that involves a transfer of electrons comes from the word ion: a charged particles ions are formed when an ionic bond occurs

Covalent Bonds a chemical bond formed by the sharing of electrons single, double, or triple bonds molecule: collection of two or more atoms covalently bonded

AGENDA Sept 23 Learning Objective: Build chemical compounds to investigate bonding between atoms. 1. Section 2-1 QUIZ 2. Finish Chemical Compounds Lab 3. Homework – Complete Lab Packet Questions DUE THURSDAY SEPT 24

2-1: Chemical Reactions any process in which a chemical change occurs reactants: elements or compounds that enter into a chemical reaction products: elements or compounds produced by a chemical reactions reactions represent chemical reactions by a chemical equation

EXIT PASS C 6 H 12 O 6 + ___ O 2  ___ CO 2 + ___ H 2 O

CONCEPT CHECK Draw a BOHR Model of Oxygen 8 Protons and 8 Neutrons How many electrons does it have?

Balanced Equation C 6 H 12 O O 2  6 CO H 2 O The same kind and number of atoms must be equal on both sides of the equation. Count the number of C, H, and O on the right side of the equation.

DO NOW Sept 20 Explain the difference between a physical change and a chemical change. Provide an example of a physical change. Provide an example of a chemical change.

DO NOW ANSWERED SEPT 20 A physical change does not change the identity of the matter. A chemical change is the change of a substance into a new substance having different physical properties. Physical Change: Tearing a piece of paper in half. Chemical change: Burning gasoline in an engine

DO NOW Sept 23 Explain how atoms react to form larger molecules.

DO NOW ANSWERED Atoms react to achieve stability. To be stable, atoms must have a completely filled outer energy level (valence shell). This is accomplished through the gaining, losing, or sharing of valence electrons.

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