Test Review PowerPoint for 5th Period

Reactants are combined together to create products What are the reactants and products in the following equations? C + 2O CO 2 2H + O H 2 O Reactants and Products Reactants ReactantProductProducts What do you notice about these equations? Coefficients-big numbers (in front) Subscripts-small numbers (behind)

Label the reactants and products on the chemical equation below: CaCO 3 CaO + CO 2 Chemical Equations Reactants Products

Mg + O 2 MgO 2H 2 O 2 2 H 2 O + O 2 2Cu 2 O + C4Cu + CO 2 FeS + 2HClFeCl 2 + H 2 S P 4 O H 2 O4H 3 PO 4 Fe 2 O 3 + CFe + CO 2 SO 2 + O 2 SO 3 Label the reactants and products. On the practice worksheet.

You must end up with the same amount you started with. Mass cannot be created or destroyed Conservation of Mass

Matter is not created or destroyed

 Goal- Have the same number of atoms on both sides of the equation.  Rules ◦ Coefficients (numbers in front) multiply ◦ You can not change subscripts (numbers behind) ◦ If there is no subscript after an atom, then you know there is only 1 atom present Balancing Equations

1. Write equation 2. Count Atoms H O H O

Balancing Equations 3. Use coefficients to balance the equation H O

2 2 H O 4 2 4

H 2 + O 2  H 2 O H 2 + Cl 2  HCl SO 2 + O 2  SO 3 Mg + O 2  MgO Balancing Equations Practice

Atoms Modern Atom Model Nucleus-Protons and Neutrons Electrons around nucleus, never know the true location

Protons Positively charged particle In nucleus Mass 1 amu

Neutrons Neutral (no) charge particle In nucleus Mass 1 amu

Electrons Negatively charged particle In electron cloud (orbitals) around the nucleus Mass 0 amu

Elements Made of atoms of one kind The type of element depends on the atomic number, or the number of protons it has Most elements occur naturally, but some have to be created in a lab

Periodic Table Elements are organized on the Periodic Table according to atomic number and properties of the element Open textbook to pages L14 – L15

Symbol The abbreviation letters used for each element

Atomic Number Number of protons (each element has a different # of protons) Number of electrons (same as # of protons so the element is electrically neutral)

Atomic Mass Mass of the Atom or # of the protons plus neutrons Each proton equals 1 amu and each neutron equals 1 amu (atomic mass unit) How do you find the average number of neutrons in an atom? atomic mass ( rounded) – atomic number

Groups Groups: or Family = columns Share similar properties Numbers on top indicate what group it is Noble gases-Group 18 (or 8A) Halogens-Group 17 (or 7A) Alkali metals-Group 1

Periods Periods = rows Atomic mass increases from left to right Number of protons increases from left to right Number of electrons in the outer shell of the atom increases from left to right Only hydrogen and helium are in the 1 st period

Look at L14 –15 or L186 – L187

Physical Properties Physical properties can be observed or measured without changing the identity of the matter. They are determined by the use of the They are a of an object. Five senses description

Examples of Physical Properties Color Smell Taste Hardness State of Matter (solid, liquid or gas) Boiling, Freezing, or Melting Point

Examples of Physical Properties Density Mass Volume Conductivity - The ability of a substance to allow the flow of energy or electricity.

Physical vs. Chemical Physical properties: observe without changing the identity of the substance Chemical properties: observe only when the identity changes How do you know if it is chemical or physical? If it CHanges, it’s CHemical Combustion of Mg strip

Chemical Properties ► Are determined by a substance’s ability to ► _______with other substances. react

Chemical properties A common chemical property is reactivity. Reactive to oxygen Reactive to air Reactive to water … Reactive to acid Notice that chemical properties aren ’ t EASY to observe, unlike physical properties.

Examples of Chemical Properties The ability to react with, _______, _________, __________ The ability to react with The ability to catch fire () air rusttarnish corroderot Water or acids flammability

Physical or Chemical Property? 1. Ability of gun powder and fire to explode. Chemical Property

Physical or Chemical Property? 2. The color of a sunset. Physical Property

Physical or Chemical Property? 3. The ability of a nail to rust. Chemical Property

Physical or Chemical Property? 4. The shape of a leaf. Physical Property

Physical or Chemical Property? 5. The ability of wood to burn. Chemical Property

Physical or Chemical Property? 6. The hardness of a diamond. Physical Property

Physical or Chemical Property? 7. The volume of your soda. Physical Property

Physical or Chemical Property? 8. The mass of two camels. Physical Property Complete Physical and Chemical Properties worksheet in your packet – page 5

A change in matter that results in one or more new substances. You change what it is. Chemical in the original substance combines with another chemical to create a new substance Chemical Changes

Evidence of Chemical Reactions or Change (2:52) Evidence of a Chemical Reactions

Evidence of Chemical Change New ________appears Bubbbles or ________ Precipitate forms (____ material) _____ is produced ______ is produced ______ is given off Difficult or impossible to __________ color fizzing solid reverse Heat Light Sound