Chap 10-Chemistry

Atoms are the smallest form of

elements

Names and SymbolsElements get their names in

different waysEach element has its own unique

symbolCapital letter indicates a new

element

Each Element is Made of A different Atom

John Dalton (Atomic Theory) said that each element is made of tiny particles called “atoms”

All of the atoms of a particular element are IDENTICAL but are different from atoms of other elements

Structure of an AtomSubatomic Particles found in the

atomName Charge Location Relative Mass

Proton positive Inside nucleus

2000

Electron negative Outside nucleus-orbit the nucleus

1 Way smaller than protons or neutrons

Neutron No charge Inside nucleus

2000

Nucleus of An AtomPositively charged nucleusContains neutrons and protons

Neutrons have no charge so overall charge for nucleus is positive

Atomic NumberThe IDENTITY of an atoms is

determined by the number of protons in the nucleus

Atomic Number- the number of protons in the nucleus

Mass NumberTOTAL number of Protons and Neutrons in the atom’s nucleus

Atomic Number Examples

(page 28)

Atomic Number

Atomic Mass

Atomic number equals the number of protons or electrons

Atomic mass equals the number of neutrons + protons.

Calculating Atomic Info.

Calculating Atomic Info.

Atom Model Rubric- Due Wed 9/7Present to class- big grade !

Atom correctly modeledCorrect number of subatomic particlesCorrect location of subatomic particles Includes Key Items used to demonstrate creativity

(not just colored on the page)Atom square includes atomic mass,

number and symbolCorrect energy levels and electrons in

each

Template- Must be in your notebook (atomic structure) general picture

Practice With Atoms Family Drawing Bohr Models

Practice Drawing Atoms with Bohr Models

More Examples page 34- drawing atoms with Bohr Models

Boron Neon

More Examples page 34- drawing atoms with Bohr Models

Helium Carbon

Tonight’s HW

Finish rest of page 34 and 35Use your periodic table to find out if the element is a solid, liquid or gas !

We’ll grade and check it tomorrow

Periodic TableDmitri Mendeleev- 1869Shows a periodic or repeating pattern of properties of the elements

Gaps- new elements discovered would complete the chart

Periodic table organizes atoms of the elements by properties and

atomic number Elements arranged by atomic number (number of protons)

Each square gives specific information about the atoms of an element

1. Number at top of the square, # of protons in the nucleus of that atom

2. Chemical Symbol- abbreviation for element’s name; contains one or two letters

Reading the Periodic Table

Some elements that have not been named are given a temporary 3 letter symbol

Name of the element is written below the symbol

The number below the symbol tells the average atomic mass of all the elements

Reading the Periodic Table

The color of the element’s symbol tells the physical state at room temperature.

White letters like H (hydrogen) indicate a gas

Blue letters indicate a liquidBlack letters indicate a solid

Reading the Periodic TableBackground colors of the square indicates whether the element is a metal, non-metal or metalloid.

Group Each column (top to bottom) is

called a group. Elements in a group share similar

chemical and physical properties Groups are read from top to

bottom The groups are labeled at the top of

the column Group are also called “FAMILIES”

PeriodEach row of the periodic table is called a period

Read from left to right

Horizontal row

Periodic Table has distinct regions

Three main regionsMetals on the leftNonmetals on the right (except hydrogen)

Metalloid between

Reactivity The element’s location on the table tells

us how reactive an element is

Reactive- how likely an element is to undergo a chemical change

Atoms in groups 1 and 17 are the

most reactive Elements in group 18 are the least

reactive

Bohr Model- Where electrons are found

Energy Superhighway Can hold 18 electrons

Energy Freeway Can hold 8 electrons

Energy Street Can hold 2 electrons

Lewis Dot Structure-

MetalsMost elements are metalsMetals conduct electricity and heat well and have a shiny appearance

Can be shaped easily by pounding, bending, or being drawn into a long wire

Reactive Metals

Group 1Alkali metalsEx: Sodium and Potassium

Group 2Alkali earth metalsLess reactive

Isotopes

Atoms of certain elements ALWAYS have the same number of protons, may not always have the same number of NEUTRONS.

Not all atoms of an element have the same MASS NUMBER

Ex: Chlorine- some have 17 protons and 18 neutrons, other chlorine atoms have 20 neutrons

Ions-formed when an atom loses or gains one or more electrons

Sodium – 11 electrons, loses an electron

Chlorine- 17 electrons, gains an electron