Elements and the Periodic Table

Chapter 4

What will we learn today?

Today we will describe the atomic theory using Cornell Notes and a timeline.

1. Development of the atomic theory

2. Atom – what is it?3. smallest particle of an element

2. Atomic theory –what is it?3. A theory based on a series of models that developed over time as scientists conducted many experiments

2. Dalton’s Atomic Theory

3. John Dalton was from England3. Chemist3. 1766-1844

3. Elements are composed of atoms3. Atoms cannot be divided3. All atoms of the same element have the same mass3. Atoms of an element cannot be changed into another element3. Compounds have ratios

2. Thomson’s model3. J.J. Thomson from England3. 1854-19403. Determined atoms have electrons

4. negatively charged particles3. Stated electrons were scattered throughout the atom.

2. Rutherford’s Model3. Ernest Rutherford from New Zealand3. 1871-19373. Gold foil experiment3. Determined positively charged particles were in the nucleus3. Protons =positive charge3. Electrons have little mass3. Model = atom mostly empty space with electrons orbiting the nucleus

Gold Foil Experiment

Rutherford Animation

http://www.mhhe.com/physsci/chemistry/essentialchemistry/flash/ruther14.swf

Rutherford’s Model

2. Bohr’s Model

3. Niels Bohr from Denmark3. 1885-19623. Electrons traveled in orbits such as planets 3. Resembled the layers in an onion

2. Cloud Model

3. 1920’s3. Electrons do not orbit the nucleus3. Electrons are found in a cloudlike region3. Movement of an electron is related to its energy level

4. each electron has a specific amount of energy contained in different levels

Cloud Model

1. Modern Atomic Model

2. James Chadwick3. 19323. English3. Discovered the NEUTRON

4. in the nucleus and no charge4. Same mass as a proton

3. Modern model is mostly empty space

3. The center of an atom is tiny3. Nucleus contains protons and neutrons3. Electrons surround the nucleus in a cloudlike region

2. Particle charges

3. Protons = positive charge3. Electrons = negative charge3. Neutrons = neutral charge3. # of Protons = # electrons 3. Elements do not have a charge

2. Particle Mass

3. Protons = 1 amu (atomic mass unit)3. Neutrons = 1 amu3. Electrons = 1/1,836 amu

2. Atomic Number – what is it?

3. Number of protons in the nucleus of an atom3. # of p’s do not change3. Also means the # of electrons

1. Isotopes and mass number

2. Isotopes – what is it?3. Atoms of the same element

that have different numbers of neutrons

3. Carbon-12 vs Carbon-132. Mass number – what is it?

3. Sum of the protons and neutrons in the nucleus of an atom

Credits

https://reich-chemistry.wikispaces.com/fall.2008.MMA.Brow.timelineGoogle images

1. Organizing the elements

2. Mendeleev’s periodic table3. Dimitri Mendeleev from

Russia3. 1869 only 63 elements

most were solid3. discovered a pattern that

applied to the elements

2. Patterns of properties3. Used the melting point, density, and color along with the atomic mass

4. the average mass of all the isotopes of an element3. He noticed a pattern of properties when arranging the elements in order of increasing atomic mass3. Constructed the first periodic table

4. arrangement of elements showing the repeating pattern of their properties.

2. Predicting new elements3. Using the groups, he could predict the elements not discovered at that time.

What will we learn today?

Today we will analyze the periodic table using Cornell Notes and a chart

2. The modern periodic table

3. Based on atomic #, not atomic mass

3. Approximately 117 elements3. Properties of an element can be

predicted from its location on the periodic table

2. Classes of elements3. Periods – what are they?

4. Horizontal rows4. metals on the left4. nonmetals on the right4. Inert gases on the far right4. Semimetals in the middle4. 7 periods

3. Groups4. Vertical columns (up and

down)4. AKA “Family”4. Contain elements with

similar characteristics

What we will learn today

Today we will Compare and Contrast the properties of metals and nonmetals using Cornell Notes, NTG and a Venn Diagram.

1. Properties of Metals and nonmetals

2. Metals – what are they?3. Elements that are good conductors of electrical current and heat.3. Shiny and bendable

2. Properties of Metals

3. Malleable – can be hammered or rolled into flat sheets or shapes3. Ductile – can be pulled out into a long wire3. Luster – shiny or glittering3. Thermal Conductivity – ability to transfer heat3. Electrical conductivity – ability to transfer electricity3. All of these are physical properties

2. Chemical properties of metals

3. Reactivity – ease and speed with which a substance reacts with other substances.3. Corrosion – Gradual wearing away of a metal due to a chemical reaction

2. Properties of nonmetals

3. Poor conductors of electric current and heat.

3. Dull and brittle3. O, N, C, S, I3. Diatomic molecule – molecule that

consists of 2 atoms4. Ex: N2, O2

2. Chemical properties of nonmetals

3. Gain or share electrons3. Rust is an example3. When nonmetals mix with metals

Chapter 4 Review

The ____ is the very small center core of an atom

Which particles in atoms have a negative electric charge?

A. ElectronsB. ProtonsC. NeutronsD. Nuclei

How many neutrons does Na contain?

The elements in the first column of the periodic table

A. Have similar propertiesB. Are in the same periodC. Have the same atomic massD. Have very similar chemical

symbols

What information in the periodic table indicates the number of protons in an atom?

A. The position of the element in its column

B. The element’s chemical symbolC. The element’s atomic numberD. The element’s atomic mass

Most metals are NOT

A. DuctileB. Good conductors of heat and

electricityC. Liquid at room temperatureD. Malleable

The elements in a group of the periodic table have similar characteristics.

True

Or

false

Which groups contain the most metals?

A. SemimetalsB. NonmetalsC. Transition MetalsD. Nobel Gases

In the periodic table, the most reactive metals are found

A. In group 1, the far leftB. Group 18, the far rightC. Groups 3-12D. Period 1, the top row

Mendeleev created the first periodic table by arranging elements in order of

A. Decreasing atomic massB. Increasing atomic massC. Increasing atomic numberD. Increasing melting points and

densities

A column of elements in the periodic table is called a group, or _________.

Fluorine, Chlorine, Bromine are part of a family called

A. Inert gasesB. SemimetalsC. HalogensD. Alkali Metals

Which of the following scientists inferred that an atom’s positive charge must be clustered in the nucleus?

A. Niels BohrB. John DaltonC. Ernest RutherfordD. J.J. Thomson

What is the atomic number for He?

Which of the following element is in a group by itself?

A. CalciumB. OxygenC. HydrogenD. Helium

How did chemists change Mendeleev’s periodic table in the early 1900’s?

A. They included chemical properties such as bonding power

B. They included physical properties such as melting point and density

C. They used atomic mass instead of atomic number

D. They used atomic number instead of atomic mass

Which scientist stated that the atomic model was like an onion?

A. BohrB. RutherfordC. ThomsonD. Dalton

Protons have no charge; they are neutral

True

Or

False

The modern periodic table is organized according to atomic mass

True

Or

False

The horizontal rows in the periodic table are knowns as groups.True

Or

False

A material is said to be ductile if it

A. Can be pulled out, or drawn , into a long wire

B. Can be hammered or rolled into flat sheets and other shapes

C. Can transfer heat or electricity to another material

D. Is a mixture of a metal with at least one other element

In an atom, the number of protons equals the number of

A. NucleiB. ProtonsC. ElectronsD. Neutrons

Each element is given a specific _____ that usually consists of one or two letters.

The two most common alkaline earth metals are

A. Copper and zincB. Iron and silverC. Sodium and potassiumD. Calcium and magnesium

The elements that do not ordinarily form compounds are

a. Elements in the carbon familyb. Metalsc. Halogensd. Inert Gases

What is an example of a diatomic molecule?

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