ATOMIC STRUCTURE

INVESTIGATION 1 Atomic Structure

What is Matter? All substances on Earth are composed of matter Matter is anything that has mass and takes up space Three Types of Matter Solid Liquid Gas

Matter In its simplest form, matter is made up of elements Elements are substances that cannot be broken down into smaller components through chemical reactions

Elements Elements are classified by their physical properties Physical Properties of matter is anything that can be observed, without chemically changing the matter density, solubility, mass, color, strength

Classification of Elements Elements are organized into a table by their physical and chemical properties Periodic Table of Elements Metals, Nonmetals (liquid, gas), and Metalloids Physical properties Metals Shiny appearance Hard or malleable Nonmetals Dull in appearance Soft and brittle

Periodic Table Periodic table has 18 vertical columns called groups Each group is labeled by a number directly above it 7 horizontal rows called periods Each period is labeled by a number directly to the left of it

Periodic Table

Elements on the Table Each element has a name, and 1-3 letter symbol for the element H, Hydrogen Each element has two numbers At the top or left representing atomic number Bottom or right representing atomic mass

Elements on the Table

FOCUS QUESTIONS Atomic Structure Investigation 1

What is an element? Substances that cannot be broken down into smaller components

What is the Periodic Table of Elements? A table that organizes elements according to their physical and chemical properties

How is the Periodic Table Arranged? Elements with similar physical and chemical properties are grouped together on the table Elements with metallic properties are grouped together on the left side of the table while elements with nonmetallic properties are grouped on the right side of the table The columns on the table are referred to as groups and the rows as periods. The elements increase in atomic number from left to right

INVESTIGATION 2 Atomic Structure

Chemical properties Property of a substance that can be observed during a chemical reaction

Properties Physical Metals Shiny appearance Hard or malleable Nonmetals Dull in appearance Soft and brittle Chemical Reactions that are observed during chemical reactions · Properties of an element are determined by the makeup of its atomic particles, atoms

Atoms At atoms is the smallest particle of an element that still has all the properties of that element Composed of three different types of smaller subatomic particles Protons (positive (+) charge) Neutrons (no charge) Electrons ( negative (-) charge) Most of an atom’s mass is located in its center or nucleus Protons and neutrons are found in the nucleus

Atomic Number and Mass Atomic Number represents the number of protons an element has Atomic Mass represents the number of protons and neutrons in the nucleus To determine the number of neutrons Subtract the atomic number from the atomic mass

Atomic Number and Mass Number of Protons 6 Number of Neutrons 6 Number of Electrons 6 Atomic Number 6 Atomic Mass 12

Electrons Electrons orbit the nucleus Extremely small subatomic particles that have a negative charge Under normally circumstances, atoms generally have the same amount of protons as electrons. Sometimes atoms lose their electrons or gain extra electrons when they interact with other substance

Isotopes and Ions Elements do not always have the same number of neutrons in their nucleus Elements that have the same number of protons but a different number of neutrons are called isotopes Atoms that don’t have the same number of electrons and protons are called ions

FOCUS QUESTIONS Atomic Structure Investigation 2

How do elements from the Nonmetals and Metal groups differ? Metals and nonmetals have different chemical properties from each other They react differently when combined with other substances

What are atoms? What types of components make up an atom? An atom is the smallest particle of an element that still has all the properties of that element Atoms are composed of three different types of subatomic particles In the nucleus are protons (+) and neutrons (no charge) Orbiting the nucleus are electrons (-) that

What information about an element can be determined by using the Periodic Table ? An element’s atomic mass is equivalent to the number of protons in its atom’s nucleus and the number of electrons normally orbiting the nucleus The number of neutrons likely to be found in its nucleus is equal to the element’s atomic number

INVESTIGATION 3 & INVESTIGATION 4 Atomic Structure

Physical Properties The ability to conduct or transmit electricity is another property of some elements Metals are very effective at conducting electricity while nonmetals are not

How do elements from the metal and nonmetal groups differ Elements from the metal and nonmetal group have different physical properties. One difference is the ability to conduct electricity

Three Divisions of Elements on the Perodic Table Division 1: Metals -Elements to the left of Groups staircase Division 2: Nonmetals- Groups on the far right side of the table Elements in Group 18 are known as the Noble Gases Rarely react chemically with another element Division 3: Metalloids- found between the metals and nonmetals; they possess properties of both metals and nonmetals B, Si, As, Te, Ge, Sb, Po, At

What is a Metalloid? An element that can have properties of both metals and nonmetals

Where are Metalloids found on the Periodic Table Found on the border between the Metals and Nonmetals

How is the Periodic Table Arranged? Separates elements into metals, nonmetals, and metalloids All of the elements on the left side of the staircase border are metals, with the exception of Hydrogen (H) Elements to the right are the nonmetals and Noble Gases Elements on the border are the metalloids