atoms and elements and compounds: are they related? bgjhs science 7 th grade
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Atoms and Elements and Compounds: Are they Related?
BGJHS Science7th Grade
Matter
• Matter is anything that has mass and volume (takes up space).
ATOMSATOMS• ALL MATTER IS MADE OF ALL MATTER IS MADE OF ATOMS• Definition: ATOMS ARE THE Definition: ATOMS ARE THE
SMALLEST PIECE OF MATTER and CANNOT BE BROKEN DOWN INTO A SIMPLER SUBSTANCE.
ATOMS HAVE ATOMS HAVE 3 BASIC PARTS (Subatomic Particles)• PROTONS• NEUTRONS• ELECTRONS
– PROTONS (POSITIVE CHARGE)– ARE FOUND IN THE NUCLEUS AND
MAKE UP MOST OF THE MASS OF THE ATOM.
– VERY IMPORTANT!!! The number of protons an atom has tells you what kind of atom it is!!!!
–NEUTRONS (NO CHARGE)• ARE FOUND IN THE NUCLEUS• MAKE UP PART OF THE MASS
OF THE ATOM
Isotopes• Atoms of the same element that have
a different number of neutrons.EX: Carbon
Carbon-12 Carbon-13 Carbon-14
Isotopes & Radioactive Decay
• Atoms are most stable when they have the same number of Pro/Neu in the nucleus…
• So, having more neutrons causes atom to be unstable & “repulsion” builds up.
• Nucleus becomes more stable when the extra particles are released & energy is given off.
• RD is the release of extra nuclear particles & energy.
– ELECTRONSELECTRONS (NEGATIVE CHARGE - )(NEGATIVE CHARGE - )•FOUND IN THE ELECTRON SHELL FOUND IN THE ELECTRON SHELL
(cloud) ORBITING THE NUCLEUS.(cloud) ORBITING THE NUCLEUS.
•TAKES UP MOST OF THE TAKES UP MOST OF THE SPACESPACE IN IN AN ATOM.AN ATOM.
Valence Electrons
• Outermost electron(s) in the cloud/shell
• 8 is the magic number!!!!!! (octet rule)
Ions
• Atom where the total number of electrons does not equal the total number of protons (atom will have a pos or neg charge)– Cation= pos (loss of e-)– Anion=neg (gain of e-)
– EX: Fe2+, Al3+, O2-
How to Find:• # of Protons
– The atomic number IS the number of protons
– Atomic number is located on the periodic table
# of Protons• If the atomic # is 7, what is the # of protons?• If the atomic # is 15, what is the # of protons?• If an atom has 22 protons, what is its atomic #.• How many protons does Oxygen have? What is
Oxygen’s atomic #?• Neon has 10 protons. What is its atomic #?• If an atom has 35 protons, what is the name of
the atom?
How to Find:• # of Neutrons
– You can find the number of neutrons by subtracting the atomic mass from the # of protons (atomic number).
atomic mass - # of protons = # of neutrons
# of Neutrons• If an atom’s mass is 9amu and has 4
protons, how many neutrons does it have?• If an atom’s mass is 14amu and has atomic
number of 7, how many neutrons does it have?
• How many neutrons does aluminum have?• How many neutrons does calcium have?• An atom has a mass of 28amu and 14
neutrons, what type of atom is it?
# of Neutrons
• If an atom of germanium has 41 neutrons and 32 protons, what is its atomic mass?
• Nickel has an atomic number of 28 and has 31 neutrons, what is its mass?
Isotopes & Mass Number
• If we have a different number of neutrons, will the mass be affected?
• EX: since C-14 has 8 neutrons, the mass number is 14amu instead of 12amu (C-12).
Isotopes• Atoms of the same element that have
a different number of neutrons.EX: Carbon
Carbon-12 Carbon-13 Carbon-14
How to Find• # of Electrons
–The # of electrons IS EQUAL to The # of electrons IS EQUAL to the # of protonsthe # of protons
# of Electrons• If Helium has 2 protons, how many
electrons does it have?• If the atomic number of magnesium is
12, how many electrons does it have?• If an atom has 21 electrons, what type
of atom is it?
How to Find:• Atomic Mass
– You can find the atomic mass by adding the # of protons and the # of neutrons
– # of protons + # of neutrons = atomic mass
Putting it all together…
Element Atomic # Atomic Mass
Proton Neutron Electron
Au 79 118Cr 52 24B 11 5
Discovery of the Atom (pg. 80)
By the early 1800’s, John Dalton proposed that all substances are made up of atoms.
In 1898, J.J. Thomson, proposed that atoms are made up of smaller parts.
In 1911, Ernest Rutherford, proposed that atoms have electrons and a positively charged nucleus.
1)All matter is made of atoms. Atoms are indivisible and indestructible.
2) All atoms of a given element are identical in mass and properties
3) Compounds are formed by a combination of two or more different kinds of atoms.
4) A chemical reaction is a rearrangement of atoms.
Dalton’s Atomic Theory
Niels Bohr’s model of the atom that shows the electrons revolving around the nucleus in circular paths called orbits.
Current Atomic Theory:
Electron Cloud ModelElectrons travel in regions of various thicknesses called clouds (shells).
Label the atom below on your packet!
What type of atom is this?
How do you know?
PIN THE NUCLEUS ON THE ATOM
Elemental Candy
• ELEMENTS ARE PURE SUBSTANCES MADE OF TWO OR MORE OF THE SAME KIND OF ATOM.
• SOME COMMON ELEMENTS – HYDROGEN (H), HELIUM (He), OXYGEN
(0),– Notice that the first letter is capital and
the next letter is lower case.
• ELEMENTS • ARE THE BUILDING BLOCKS OF MATTER.• CANNOT BE BROKEN DOWN INTO A SIMPLER
SUBSTANCE.• HAVE THEIR OWN UNIQUE SET OF
PROPERTIES THAT NO OTHER ELEMENT HAS.
ELEMENTS
• There are 92 naturally occurring elements on the periodic table. This means they are in nature and not made in a laboratory by scientists.
• As of the year 2015 there are 118 known elements but there are gaps.
Elements
• Most Elements– are rarely found alone in nature– react with water or oxygen– easily undergo a chemical change
Atoms and Elements Activity
• As a group, look at the food labels on the items at your table. Make a list of the items in the left hand side column and in the right hand side column make a list of any elements found in that substance.
• You may use your periodic table to help you identify the elements.
The food item would be:
Cooked Ham
What are the elements that are found on this food label?
QUESTIONS????• What are the most commonly occurring
elements in the food labels?• What items seemed to have the most
amount of elements in them?• Can you predict what that means about
the food item?• Why do you think the baby formula has
such a variety of elements?• Can you predict what the other items on
the food label are if they are not elements?
PERIODIC PATTERNS
Periodic Table
• The periodic table is an organized table of each element.
• Each box gives information about each type of element found on Earth.
9.17.00 1:37 PM41 3.3 Periodic Table
Dmitri Mendeleev (1869)(1869)In 1869 Mendeleev and Lothar Meyer In 1869 Mendeleev and Lothar Meyer (Germany) published nearly identical (Germany) published nearly identical classification schemes for elements known classification schemes for elements known to date. The periodic table is base on the to date. The periodic table is base on the similarity of properties and reactivities similarity of properties and reactivities exhibited by certain elements. Later, Henri exhibited by certain elements. Later, Henri Moseley ( England,1887-1915) established Moseley ( England,1887-1915) established that each elements has a unique atomic that each elements has a unique atomic number, which is how the current periodic number, which is how the current periodic table is organized.table is organized.
http://www.chem.msu.su/eng/misc/mendeleev/welcome.html
• ELEMENTS ARE ORGANIZED IN THE PERIODIC TABLE ACCORDING TO INCREASING ATOMIC NUMBER.
• ELEMENTS ARE ORGANIZED IN THE PERIODIC TABLE OF ELEMENTS ACCORDING TO THEIR SIMILAR CHARACTERISTICS
Elements & their symbolsSOME COMMON ELEMENTS
HYDROGEN (H), HELIUM (He), OXYGEN (0),
Notice that the first letter is capital and the next letter is lower case.
Gold- Au (Aurum)
Iron- Fe (Ferrum)
Lead- Pb (Plumbum)
Element Info in Each Box
Atomic MassAtomic NumberSymbol Name
Arrangement of the Periodic table
Periods – Rows are called periods. The elements in these rows change conductivity and number of electrons as you move across the table.
Groups – Columns are called groups or families. These elements have the same properties because of the number of electrons.
How is the Periodic Table Organized?
Even though they skip some squares in between, all of the rows go left to right. When you look at a periodic table, each of the rows is considered to be a different period
Periods
• There are 7 periods. Each period represents the number of electron shells.– Elements in period 1 have 1 electron shell.– Elements in period 5 will have 5 electron
shells.
9.17.00 1:37 PM49 3.3 Periodic Table
Across the Periodic Across the Periodic TableTable
Periods:Periods: Are arranged horizontally across the Are arranged horizontally across the periodic table (rows 1-7)periodic table (rows 1-7)
These elements have the same number of valence shells.These elements have the same number of valence shells.1
IA18
VIIIA
12
IIA13
IIIA14
IVA15VA
16VIA
17VIIA
2
33
IIIB4
IVB5
VB6
VIB7
VIIB8 9
VIIIB10 11
IB12IIB
4
5
6
7
2nd Period
6th Period
Groups When a column goes from top to bottom, it's called a group or family.
Groups are often called families because these elements seem to be related.
**Elements in the same group show similarities in their chemical and physical properties.
There are 8 main groups across the periodic table. Groups or families have the same number of electrons in the outermost shell. The group number tells you how many electrons are in the outermost shell.
Group 1 has 1 electron in outermost shell.
Group 4 will have 4 electrons in outermost shell.
9.17.00 1:37 PM52 3.3 Periodic Table
Down the Periodic Down the Periodic TableTable
Family:Family: Are arranged vertically down the periodic table Are arranged vertically down the periodic table (columns or (columns or group, 1- 18 or 1-8 A,B)group, 1- 18 or 1-8 A,B)These elements have the same number electrons in the outer most shells, the valence These elements have the same number electrons in the outer most shells, the valence shell.shell.
1IA
18VIIIA
12
IIA13
IIIA14
IVA15VA
16VIA
17VIIA
2
33
IIIB4
IVB5
VB6
VIB7
VIIB8 9
VIIIB10 11
IB12IIB
4
5
6
7
Alkali Family: 1 e- in the valence shell
Alkali Family: 1 e- in the valence shell
Halogen Family: 7 e- in the valence shell
Halogen Family: 7 e- in the valence shell
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Reading the Periodic Table: Reading the Periodic Table: ClassificationClassification
Nonmetals, Metals, Metalloids, Noble gases
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Periodic Table: Periodic Table: Metallic Metallic arrangementarrangement
Layout of the Periodic Table: Metals vs. nonmetals
1IA
18VIIIA
12
IIA13
IIIA14
IVA15VA
16VIA
17VIIA
2
33
IIIB4
IVB5
VB6
VIB7
VIIB8 9
VIIIB10 11
IB12IIB
4
5
6
7
MetalsMetalsNonmetalsNonmetals
9.17.00 1:37 PM55 3.3 Periodic Table
Infamous Families of the Periodic Infamous Families of the Periodic TableTable
Notable families of the Periodic Table and some important members:
1IA
18VIIIA
12
IIA13
IIIA14
IVA15VA
16VIA
17VIIA
2
33
IIIB4
IVB5
VB6
VIB7
VIIB8 9
VIIIB10 11
IB12IIB
4
5
6
7
Alkali
Alkaline (earth)
Transition MetalsTransition Metals
Noble GasNoble GasHalogenHalogen
ChalcogensChalcogens
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Alkali GroupAlkali Group
-Group #1-1 valence electron in outer shell-very reactive with water & other elements-low densities & melting points
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Alkaline Earth GroupAlkaline Earth Group
-Group #2-2 valence electrons in outer shell-very reactive but not as much as alkali-denser, harder & higher melting points
9.17.00 1:37 PM58 3.3 Periodic Table
Transition MetalsTransition Metals
-Groups 3-12-Valence electrons vary-Usually found combined with other elements-higher melting points, good conductors
9.17.00 1:37 PM59 3.3 Periodic Table
Halogen GroupHalogen Group
-Group #17-7 valence electrons in outer shell-most combined to make salts (salt formers)-most are non-metals
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Noble Gas GroupNoble Gas Group
-Group # 18-8 valence electrons in outer shell (the happy gases! )
-NOT REACTIVE
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Periodic Table: Periodic Table: Metallic Metallic arrangementarrangement
Layout of the Periodic Table: Metals vs. nonmetals
1IA
18VIIIA
12
IIA13
IIIA14
IVA15VA
16VIA
17VIIA
2
33
IIIB4
IVB5
VB6
VIB7
VIIB8 9
VIIIB10 11
IB12IIB
4
5
6
7
MetalsMetalsNonmetalsNonmetals
The Periodic Table Of Elements
Elements are classified:*Metals*Nonmetals*Metalloids
Xenon
Scandium
Properties of a metal
*Good conductors – conducts heat or electricity*Malleable - flattened*Ductile – can be made into wires*Shiny- you can see you reflection
Iron
Gold
Magnesium
Properties of a Nonmetal*Not malleable – cannot be flattened*Not shiny*Poor conductors
Helium
Chlorine
Bromine
Properties of Metalloids
•Semiconductors – Average conductors•Shiny but brittle
ArsenicSilicon
Boron
Periodic Table: Metallic arrangement• Layout of the Periodic Table: Metals vs. nonmetals
1IA
18VIIIA
12
IIA13
IIIA14
IVA15VA
16VIA
17VIIA
2
33
IIIB4
IVB5
VB6
VIB7
VIIB8 9
VIIIB10 11
IB12IIB
4
5
6
7
MetalsMetalsNonmetalsNonmetals
GOLD (AU)
Sulfur
Silver
ELEMENTS IN OUR BODIES
IODINE
• 1.Oxygen (65%) • 2.Carbon (18%) • 3.Hydrogen (10%) • 4.Nitrogen (3%) • 5.Calcium (1.5%) • 6.Phosphorus (1.0%) • 7.Potassium (0.35%) • 8.Sulfur (0.25%) • 9.Sodium (0.15%) • 10.Magnesium (0.05%) • 11.Copper, Zinc, Selenium, Molybdenum, Fluorine, Chlorine,
Iodine, Manganese, Cobalt, Iron (0.70%) • 12.Lithium, Strontium, Aluminum, Silicon, Lead, Vanadium,
Arsenic, Bromine (trace amounts)
99% of the mass of the human body is made up of only six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Every organic molecule contains carbon. Since 65-90% of each body cell consists of water (by weight), it isn't surprising that oxygen and hydrogen are major components of the body
Elements in the body
Oxygen Carbon Hydrogen Nitrogen
Calcium Phosphorus Potassium Sodium
Chlorine Magnesium Sulfur
GASESGASES
FLUORINE KRYPTON
NEON
NITROGEN
Atoms to Elements to ???
• ELEMENTS & COMPOUNDS ARE THE BASIC BUILDING BLOCKS OF MATTER
• EACH ELEMENT & COMPOUND HAS SPECIFIC PROPERTIES