Upload
uma
View
48
Download
0
Tags:
Embed Size (px)
DESCRIPTION
Chapter 4.1 / 4.2 Structure of an Atom OBJECTIVES Describe Dalton’s Atomic Theory. Describe and illustrate the structure of an atom – define the subatomic particles of an atom. Structure of an Atom. - PowerPoint PPT Presentation
Citation preview
Chapter 4.1 / 4.2Structure of an Atom
OBJECTIVES1. Describe Dalton’s Atomic Theory.2. Describe and illustrate the structure of an atom
– define the subatomic particles of an atom
Structure of an Atom• Dalton’s Theory: all matter is made up of
individual particles called ______________, which cannot be divided.– All ______________are composed of atoms– All atoms of the same element have the same mass,
and atoms of different elements have different masses
– ____________________ contain atoms of more than one element• In a particular compound, atoms of different elements
always combine in the same way
Structure of an Atom• Atoms are made of subatomic particles:
_____________, ____________ and ____________– _______________ – neutral subatomic particle found
in the nucleus of an atom
– _____________ – positively charged subatomic particle found in the nucleus of an atom
– _____________ – negatively charges subatomic particle found in the space outside the nucleus
Structure of an Atom
• The ___________ charge of an atom is not evenly spread throughout the atom.
• Positive charge is concentrated in a very small, ______________ area.
• The __________________ of the atom is a dense, positively charged mass located in the center of the atom.
Structure of an Atom• neutrons, protons and electrons can be
distinguished by _____________, ____________, and ______________in the atom.
• _________________: the number of protons in an atom of that element– Atoms of different elements have different
___________________________.• ___________________(atomic mass): sum of
the _____________ and the _______________ in the nucleus of the atom
Structure of an Atom
• ______________________: atoms of the same element that have different numbers of neutrons and different _____________ numbers– Isotopes of an element have the same
_________________number but different _________________ numbers because they have different numbers of neutrons
Chapter 4.3 Modern Atomic Theory
OBJECTIVES1. Describe Bohr’s model of the atom2. Describe the electron cloud model
Modern Atomic Theory (4.3)• ___________________ Model of the Atom– A description of the ___________________of
electrons in an atom– Electrons move with __________________ speed in
______________________ orbits around a nucleus (like planets around a sun)
Bohr Model Continued
– Each electron in an atom has a specific amount of energy – _________________________________: the possible energies that electrons in an atom can have
**An electron in an atom can move from one energy level to another when the atom ________________ or ___________________energy
Bohr’s Model of the Atom
____________________
____________________________ gain or lose energy when they move between fixed energy levels
Bohr Model
Electron Cloud Model– ______________________________: a visual model of the
most likely locations for electrons in an atom
Scientists use the electron cloud model to describe the ___________________ locations of electron around the nucleus
The _____________ contains protons and neutrons
The probability of finding an electron is higher in the _________________ regions of the cloud.
Electron Cloud Model
Electron Cloud Model
• Atomic Orbitals– The electron cloud represents all the
__________________________ in an atom– ___________________________: a region of
space around the nucleus where an electron is likely to be found
• An electron cloud is a good ____________________ of how electrons ________________________ in their orbitals
• Electron Configurations– ______________________________: the arrangement
of electrons in the orbitals of an atom
The most ________________________ electron configuration is the one in which the electrons are in orbitals with the ____________________________ possible energies..
When all the electrons in the atom have the lowest possible energies, the atom is in its _________________________________________.
Chapter 5.1 / 5.2The Periodic Table
OBJECTIVES1. Describe the arrangement of elements in the modern periodic
table.2. Describe the general properties of metals, nonmetals and
metalloids.3. Describe how the properties of elements change across a period
in the periodic table
• Mendeleev’s Periodic Table– Mendeleev arranged the elements into rows in
order of __________________ mass so that elements with ________________ properties were in the same ____________________
______________________: is an arrangement of elements in columns, based on a set of properties that _________________ from row to row.
Modern Periodic Table• Mendeleev developed his periodic table before the discovery
of protons – he did not know that all atoms of an element have the same number of protons
• In the modern periodic table, elements are arranged by increasing atomic number (number of __________________________)
________________________: each row in the table of elements
________________________: each column on the periodic table
• Properties of elements repeat in a ________________________ way when __________________ ___________________ are used to arrange elements into groups
This pattern of repeating properties is the ____________________________
_____________________________is a value that depends on the distribution of an element’s isotopes in nature and the masses of those isotopes
____________________________– is defined as one twelfth mass of a carbon-12 atom
There are four pieces of information for each element
________________
__________________
__________________
_________________
The Periodic Law• Each row in the table of elements is a
________________________• Each column in the periodic table is called a
______________________
Classes of Elements– Elements are classified as ________________________,
___________________________, and ___________________________
_________________________________: are elements that are good _______________________________ of electric current and heat - except for mercury, metals are ___________________________ at room temp - most metals are __________________________ - most metals are __________________________ (they can be drawn into thin wires)
____________________________________ are elements that form a bridge between the elements on the left and right sides of the table
_____________________________ : are elements that are ____________________ conductors of heat and electric current - non-metals have _____________________________ points – many are gases at room temperature - all the ____________________ in the periodic table are non-metals
____________________________: are elements with properties that fall between those of metals and non-metals
Across a period table, from left to right, the elements become ____________________ metallic and ________________ non-metallic in their properties
Chapter 5.3Representative Groups (periodic table)
OBJECTIVES
1. Identify the number of valence electrons in certain groups on the periodic table.
2. Predict the reactivity of some elements based on their location within a group.
REPRESENTATIVE GROUPS
______________________Elements in a group have similar properties because they have the
same number of ____________________________ electrons.
___________________________: an electron that is in the highest occupied energy level of an atom - these electrons play a key role in
chemical reactions
The ___________________________ are numbered 1-8 - this is the number of valence electrons in an electron configuration for
the element in that group
______________________
♦ the elements in Group 1A ♦ these metals have a single ___________
valence electron and are extremely reactive - they are only found as compounds in
________________ (example: NaCl - salt)
♦ the reactivity of alkali metals _________________ from the top of Group 1A to
the bottom
______________________
♦ the elements in Group 2A ♦ all alkali earth metals have
____________valence electrons
♦ the differences in reactivity among the alkaline earth metals are shown by the ways they react with
_______________________
______________________
♦ the elements in Group 3A ♦ these elements have _____________ valence
electrons ♦ _____________________________ is the most
abundant metal in the Earth’s crust
______________________________
♦ the elements in Group 4A ♦ these elements have ______________ valence
electrons ♦ the metallic nature of the elements
___________________________ from top to bottom within the group
♦ except for water, most of the compounds in the body contain _______________________________
_____________________♦ the elements in Group 5A♦ these elements have ________ valence electrons♦ includes elements with a wide range of physical properties♦ ______________________ and ___________________ are the most important elements in Group 5A
_____________________ the elements in Group 6A these elements have six __________ valence electrons____________________ is the most abundant element in the Earth’s crust• complex form of life need oxygen to stay
alive because oxygen is used to release stored energy in food
_________ was one of the first discovered elements discovered because it is found in large natural deposits
______________________♦ the elements in Group 7a♦ these elements have _________valence electrons highly reactive non-metals (fluorine and chlorine are the most reactive) – react easily with ___________________
♦ despite their physical differences, the halogens have ___________________ chemical properties
____________________♦ the elements in Group 8A♦ these elements have _________valence electrons except for helium (He) which has ____________♦ the noble gases are __________________ and ____________________ and extremely unreactive
When electric current is passed through the _________________ gases, they emit different colors
helium – pink krypton - white
neon – orange / red xenon - blue
argon – lavender