2 How many different types of atoms is helium made up of 3 Draw the Bohr model for helium there are two neutrons in helium Todays Objectives SWBAT explain that a chemical formula describes the combination of two or more elements ID: 783240
Download The PPT/PDF document "Catalyst 1. He is the ___________ for th..." is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Catalyst
1. He is the ___________ for the element Helium.2. How many different types of atoms is helium made up of?3. Draw the Bohr model for helium (there are two neutrons in helium).
Slide2Today’s Objectives
SWBAT explain that a ‘chemical formula’ describes the combination of two or more elements.SWBAT identify the number of elements in a chemical formula and how many of each element is present.
SWBAT
differentiate between a chemical symbol and a chemical formula
SWBAT classify common substances as elements or compounds based on their chemical symbols or formulas.
Slide3A
molecule
is formed when
two SAME or different elements
combine
For examples when two elements of oxygen come together, they form a molecule of oxygen (0
2
)
Slide4Common Examples of Elements
H
2
-
A molecule of
Hydrogen
O
2
-
A molecule of
Oxygen
N
2
-
A molecule of
Nitrogen
Slide5Compounds
When
two or more
DIFFERENT elements
chemically
combine
, they form a compoundFor example when the elements sodium (Na) and chlorine (
Cl
) combine they
form
NaCl
(Common salt)Other examples: Ex: CO2, H2O
Slide6Common Examples of Compounds
NaCl
-
Common Salt
H
2
O-
Water
CO
2
-
Carbon dioxide
Slide7Compounds
When elements are chemically combined, they form compounds
that have
completely different properties than the uncombined elements that make them up.
Slide8For example, the element sulfur is a yellow solid and the element silver is a shiny metal.
Compounds
Slide9Compounds
But when silver and sulfur combine, they form a compound called silver sulfide, Ag
2
S. You would call this black compound tarnish.
Slide10Chemical Symbol
What was that again??!!?
Slide11Chemical Formula
A combination of chemical symbols used to represent a
compound
(this means it represents a combination of two or more different elements chemically combined)
Contains the ratio of the
elements
for the compound.If the compound contains more than one particular element, this quantity is indicated using a subscript
Slide12Subscript
A number placed to the lower right of a chemical
symbol
used
to
shows
how many atoms of each element are present.H2
O
CO
2
Slide13Compounds
For example, part of the gas you exhale when you breathe is carbon dioxide. Its chemical formula is CO
2
.
Slide14Compounds
CO
2
The number 2 below the symbol for oxygen tells you that the ratio of carbon to oxygen is 1 to 2. There are 2
oxygens
for every 1 carbon. (If there is no number after an element’s symbol, the number 1 is assumed.)
Slide15Compounds
If a different ratio of carbon atoms to oxygen atoms are seen in a
formula, you have a different compound. For example, carbon monoxide – a gas produced in car engines – has the formula CO.
Slide16Cold Call
Tell me whether it is an element or compound
O
H
2
O
CO2
NaCl
Slide17Drawing!
Slide18Drawing
ElementsAtoms are represented by single circles. Circles of the same color represent atoms of the same element
.
Slide19Drawing
MoleculesMolecules are represented by two or more circles joined togetherMolecules of the same element are represented by two or more circles of the same size and color joined together
Slide20Drawing
CompoundsMolecules of compounds are represented by two or more circles of different sizes and colors joined together
Slide21Drawing Elements and Compounds
Slide22Drawing Elements and Compounds- Are you with me?
Slide23Slide24Whiteboards
Work with the person next to you to correctly answer the questionsYou will have 30sec per questionAlternate who is writing each answer
Slide25Whiteboard Time
Which of the following statements describes elements?A. All of the atoms in the same element are differentB. Elements can be broken down into simpler substancesC. Elements have unique sets of properties
D. Elements cannot be joined together in chemical reaction
Slide26Whiteboard Time
Which of the following substances can be separated into simpler substances by chemical means?A. Sodium (Na)B. Salt waterC. Gold
Slide27Draw a molecule of water (H
2
O)
Slide28Whiteboard Time
Neon gas contains which of the following?A. One kind of atomB. A mixture of substancesC. AirD. Many different types of atoms
Slide29Whiteboard Time
Which statement best describes what the planet Saturn, a lizard, and a steaming kettle have in common?A. All are made of atoms. B. All are multi-cellular organisms. C. All are at the same internal temperature.D. All produce their own energy without help.
Slide30Whiteboard Time
Which substance is classified as an element?A. NaCl B. COC. H2
O
D. Li
Slide31Whiteboard Time
If two poisonous elements are combined chemically, which of the following would be true of the resulting compound?A. The compound will be more poisonous than the original elementsB. The compound will be as poisonous as the original elementsC. The compound may or may not be poisonous
D. The compound will not be poisonous
Slide32Whiteboard Time
1. How many elements of carbon are in C6H12O6 ?2. How many different elements are in C
6
H
12
O
6 ?
Slide33BEAST QUESTION!
Draw the molecules and compounds of the chemical reaction: 2Na + Cl2 2 NaCl
Slide34BEAST QUESTION!
Slide35Independent Practice
Complete the worksheet on your own and silentlyWrite in your notebook if you need more room for the Venn diagram Show Ms. P when you are finished