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 England 3. Chemist

3. Elements are composed of atoms 3. Atoms cannot be divided 3. All atoms of the same element have the same mass 3. Atoms of an element cannot be changed into another element 3. Compounds have ratios

2. Thomson’s model 3. J.J. Thomson from England Determined atoms have electrons 4. negatively charged particles 3. Stated electrons were scattered throughout the atom.

2. Rutherford’s Model 3. Ernest Rutherford from New Zealand Gold foil experiment 3. Determined positively charged particles were in the nucleus 3. Protons =positive charge 3. Electrons have little mass 3. Model = atom mostly empty space with electrons orbiting the nucleus

Gold Foil Experiment

Rutherford Animation essentialchemistry/flash/ruther14.swf

Rutherford’s Model

2. Bohr’s Model 3. Niels Bohr from Denmark Electrons traveled in orbits such as planets 3. Resembled the layers in an onion

2. Cloud Model ’s 3. Electrons do not orbit the nucleus 3. Electrons are found in a cloudlike region 3. 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 Chadwick English 3. Discovered the NEUTRON 4. in the nucleus and no charge 4. Same mass as a proton 3. Modern model is mostly empty space

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

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

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

2. Atomic Number – what is it? 3. Number of protons in the nucleus of an atom 3. # of p’s do not change 3. 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 Mass number – what is it? 3. Sum of the protons and neutrons in the nucleus of an atom

Credits chemistry.wikispaces.com/fall.2008.MM A.Brow.timeline Google images

1. Organizing the elements 2. Mendeleev’s periodic table 3. Dimitri Mendeleev from Russia only 63 elements most were solid 3. discovered a pattern that applied to the elements

2. Patterns of properties 3. Used the melting point, density, and color along with the atomic mass 4. the average mass of all the isotopes of an element 3. He noticed a pattern of properties when arranging the elements in order of increasing atomic mass 3. Constructed the first periodic table 4. arrangement of elements showing the repeating pattern of their properties.

2. Predicting new elements 3. 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 elements 3. Properties of an element can be predicted from its location on the periodic table

2. Classes of elements 3. Periods – what are they? 4. Horizontal rows 4. metals on the left 4. nonmetals on the right 4. Inert gases on the far right 4. Semimetals in the middle 4. 7 periods

3. Groups 4. 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 shapes 3. Ductile – can be pulled out into a long wire 3. Luster – shiny or glittering 3. Thermal Conductivity – ability to transfer heat 3. Electrical conductivity – ability to transfer electricity 3. 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 brittle 3. O, N, C, S, I 3. Diatomic molecule – molecule that consists of 2 atoms 4. Ex: N 2, O 2

2. Chemical properties of nonmetals 3. Gain or share electrons 3. Rust is an example 3. 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. Electrons B. Protons C. Neutrons D. Nuclei

How many neutrons does Na contain?

The elements in the first column of the periodic table A. Have similar properties B. Are in the same period C. Have the same atomic mass D. 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 symbol C. The element’s atomic number D. The element’s atomic mass

Most metals are NOT A. Ductile B. Good conductors of heat and electricity C. Liquid at room temperature D. Malleable

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

Which groups contain the most metals? A. Semimetals B. Nonmetals C. Transition Metals D. Nobel Gases

In the periodic table, the most reactive metals are found A. In group 1, the far left B. Group 18, the far right C. Groups 3-12 D. Period 1, the top row

Mendeleev created the first periodic table by arranging elements in order of A. Decreasing atomic mass B. Increasing atomic mass C. Increasing atomic number D. 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 gases B. Semimetals C. Halogens D. Alkali Metals

Which of the following scientists inferred that an atom’s positive charge must be clustered in the nucleus? A. Niels Bohr B. John Dalton C. Ernest Rutherford D. J.J. Thomson

What is the atomic number for He?

Which of the following element is in a group by itself? A. Calcium B. Oxygen C. Hydrogen D. 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. Bohr B. Rutherford C. Thomson D. 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. Nuclei B. Protons C. Electrons D. 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 zinc B. Iron and silver C. Sodium and potassium D. Calcium and magnesium

The elements that do not ordinarily form compounds are a. Elements in the carbon family b. Metals c. Halogens d. Inert Gases

What is an example of a diatomic molecule?

Test Thursday! Notebooks due Thursday! Review sheets are online!