TAKS BLITZ Chemistry (Mrs. Balogun)

Physical vs. Chemical Properties Physical Properties Melting Point Boiling Point Color Density Viscosity Chemical Properties Reactivity Flammability

Chemical Properties Reactivity : Refers to what a given substance will react with Flammability : Refers to the temperature at which a substance will ignite or burn.

Physical Properties Melting Point : The temperature at which a given substance melts Boiling Point : The temperature at which a given substance begins to boil

Physical Properties (cont.) Density: A ratio of the mass of an object and the object’s volume Viscosity: Is the resistance of a fluid to flow.

Exploring Viscosity Which liquid has the highest viscosity in the following comparisons? Let’s Explore Dish Detergent or Vinegar? Honey or Alcohol?

Exploring Density What is the density of water? How can it be calculated? Let’s Explore How could the density of a regular and irregular object be determined? Let’s explore

Viscosity Vs. Density What is the relationship between viscosity and Density ( Direct or Indirect) ? They have a direct relationship. As The density of a liquid increases its’ viscosity also increases. In other words liquids that are very dense have high viscosities and are therefore resistant to flow.

Physical Change A change in a substance that does not create a new substance. The substance may change states/phases. However, the substances chemical makeup does not change. The process can be reversed.

Chemical Change A change in which a new substance is created. The chemical composition of the substance is changed. There are at least 4 signs that would indicate a chemical change. Let’s see if we can identify them !

Breaking Pencil into 2 Frying an egg Burning of wood Melting of ice Milk turning sour Water freezing and forming ice

PERIODIC TABLE What is the Periodic Table? This is a table that lists the elements in increasing order of their atomic number. Each row across is called a period. Each column down is a group.

Each element has: - An Atomic Number = # of Protons (Electrons) - A Mass Number = # of Proton + Neutrons (APEMAN) For example: 6 C Carbon Atomic Number Symbol Name Average Atomic mass Atomic Number & Mass

Element Groups Group 1 elements are known as the Alkali Metals. They are the most reactive. Group 2 elements are known as Alkali Earth Metals they are highly reactive, but less reactive than the Alkali Metals. Group 17 elements are called the Halogens. Group 18 elements are called the Noble Gases. These elements are the least reactive. Group 3-12 are called Transition Elements.

Elements in the same group have -similar chemical properties -same # of outer electron (valence electrons) Any atom that does not have fully filled outermost energy level undergoes ionization- (process of adding or removing electrons from an atom or group of atoms) When an atom loses or gain electrons it changes to an ion. This ion could be +ve or –ve depending on whether it is gaining or losing.

Chemical Bonding Ionic --- Bond between a metal & a nonmetal This involves transfer of electrons from metals to nonmetals Covalent --- Bond between 2 nonmetals this involves the sharing of electrons between the two nonmetals.

Let us identify them 1. N 2 O 5 6.NaBr 2. Na 2 SO 4 7.P 4 O 6 3. CCl 4 8.Cl2 O 7 4. CaCl 2 9. As 2 O 3 5. SO 3 10.Cu(NO 3 ) 2

Naming compounds We use prefix for naming covalent compounds We do not use prefix to name ionic compounds Let us practice with these examples

Let us name the following compounds 1. N 2 O 5 6.NaBr 2. Na 2 SO 4 7.P 4 O 6 3. CCl 4 8.Cl2 O 7 4. CaCl 2 9. As 2 O 3 5. SO 3 10.Cu(NO 3 ) 2

Law of conservation of mass Mass is neither created nor destroyed during chemical reactions. Mass of reactants = Mass of products # of atoms of each elements must be equal on the reactants and the products sides 2Cu + O 2  2CuO 27g 32g  ?

Balancing of equation In balancing an equation, do not change the subscript Add only coefficients. 2Cu + O 2  2CuO

Atomic Number & Mass Each element has: - An Atomic Number = # of Protons (Electrons) - A Mass Number = # of Proton + Neutrons (APE/MAN) – Let’s Practice! For example: 6 C Carbon C Carbon Atomic Number Symbol Name Average Atomic mass

The Basis for Elements Atomic Number – # of protons – Determines the atom type/element Mass Number – # of protons + # of neutrons – Determines the Atomic Mass but not the same as the Atomic Mass Atomic Mass – Average mass of the different isotopes of an element

PROTONNEUTRON ELECTRON Sub-atomic particles Positively charged (+)Neutral/No charge Negatively charged (-) Identifies the element At nucleus Determines mass number identifies the isotope Determines charge/ion formation Orbits nucleus Is the atomic number Determines reactivity Composes the atom Venn Diagram of the Sub-Atomic Particles

Element Groups Group 1 elements are known as the Alkali Metals. They are the most reactive. Group 2 elements are known as Alkali Earth Metals they are highly reactive, but less reactive than the Alkali Metals. Group 17 elements are called the Halogens. Group 18 elements are called the Noble Gases. These elements are the least reactive. Group 3-12 are called Transition Elements

Elements in the same group/family have - similar chemical properties - same number of valence electrons & oxidation number Any atom that does not have fully filled outermost energy level may undergo ionization ---process of adding or removing electrons from an atom or group of atoms When an atom loses or gain electrons it changes to an ion. This ion could be positively or negatively charged depending on whether it is gaining or losing.

7D IPC Which of the following groups contains members with similar chemical reactivity? A. Li, Be, C B. Be, Mg, Sr C. Sc, Y, Zr D. C, N, O

7D IPC 11/04

7D IPC

7D IPC J 11/05

7D IPC H 11/05

Law of conservation of mass Mass is neither created nor destroyed during chemical reactions. Mass of reactants = Mass of products # of atoms of each elements must be equal on the reactants and the products sides 2Cu + O 2  2CuO 27g 32g  ?

Balancing of equation In balancing an equation, do not change the subscript Add only coefficients. Cu + O 2  CuO – Let’s Practice by making a reactants/products chart!

An unknown silvery powder has a constant melting point and does not chemically or physically separate into other substances. The unknown substance can be classified as — A an element B a compound C a mixture D an alloy

The first equation represents photosynthesis. Plants use energy from sunlight to produce sugar and oxygen from carbon dioxide and water. The second equation represents aerobic respiration. Plants and animals release stored energy in a reaction between sugar molecules and oxygen. This reaction produces carbon dioxide and water. 2. Oxygen (O2) is an example of — A an alloy B a molecule C a salt D a mixture

8C IPC