TAKS BLITZ

Chemistry 2010-2011 (Mrs. Balogun)

Physical vs. Chemical Properties

Physical PropertiesMelting PointBoiling PointColorDensityViscosity

Chemical Properties

ReactivityFlammability

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

CCarbon12.011

Atomic Number

Symbol

NameAverage 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. N2O5 6.NaBr

2. Na2SO4 7.P4O6

3. CCl4 8.Cl2 O7

4. CaCl2 9. As2O3

5. SO3 10.Cu(NO3)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. N2O5 6.NaBr

2. Na2SO4 7.P4O6

3. CCl4 8.Cl2 O7

4. CaCl2 9. As2O3

5. SO3 10.Cu(NO3)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 + O2 2CuO

27g 32g ?

Balancing of equation

In balancing an equation, do not change the subscript

Add only coefficients. 2Cu + O2 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

CCarbon12.011

6

CCarbon12.011

Atomic Number

Symbol

NameAverage 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

PROTON NEUTRON

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 + O2 2CuO

27g 32g ?

Balancing of equation

In balancing an equation, do not change the subscript

Add only coefficients. Cu + O2 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 alloyB a moleculeC a saltD a mixture

8C

IPC