STAAR Need to Know1 STAAR Reporting Category 1 Matter & Energy Middle School Science Science STAAR Need to Know

STAAR Need to KnowSTAAR Need to Know 11

STAAR Reporting Category 1STAAR Reporting Category 1Matter & EnergyMatter & Energy

Middle School ScienceMiddle School Science

Science STAAR Need to KnowScience STAAR Need to Know


Atomic TheoryAtomic Theory

Atoms are building blocks of elements Atoms are building blocks of elements

Atoms in each unique element are the same. Atoms in each unique element are the same. (Ex: Every (Ex: Every

oxygen element has the same # of protons)oxygen element has the same # of protons)

Atoms are different from atoms of other elements Atoms are different from atoms of other elements (Ex: (Ex:

Hydrogen has a different # of protons than oxygen)Hydrogen has a different # of protons than oxygen)

Two or more different atoms bond in simple ratios to form Two or more different atoms bond in simple ratios to form

compounds compounds (Ex: Hydrogen & oxygen can chemically combine to (Ex: Hydrogen & oxygen can chemically combine to

form water- Hform water- H22O )O )




Atoms and ElementsAtoms and Elements


Atomic Particle ChargesAtomic Particle Charges

Protons Positive Protons Positive ++

Neutrons Neutral Neutrons Neutral ==

Electrons Negative Electrons Negative --


Location of Subatomic ParticlesLocation of Subatomic Particles

1010-13 -13 cmcm

electronselectrons

protonsprotons

neutronsneutrons

1010-8 -8 cmcm

nucleus


Location of Atomic ParticlesLocation of Atomic Particles

Inside the NucleusInside the Nucleus

ProtonsProtons with a Positive with a Positive chargecharge

ANDAND

NeutronsNeutrons with a Neutral with a Neutral charge –that means they charge –that means they do not have a chargedo not have a charge

Outside the Nucleus-Outside the Nucleus- in in electron cloudelectron cloud

ElectronsElectrons with a with a Negative chargeNegative charge

Did you know electrons Did you know electrons are very, very small and are very, very small and move very, very fast???move very, very fast???


Periodic SquaresPeriodic Squares

The periodic square for an element The periodic square for an element can tell you lots of information about that atom.can tell you lots of information about that atom.

Atomic number = # of protons Atomic number = # of protons

Atomic number = # of electronsAtomic number = # of electrons

That means in a neutral (uncharged) atom the # of That means in a neutral (uncharged) atom the # of protons and electrons are always the SAME!!!!protons and electrons are always the SAME!!!!

1111

NaNa

22.9922.99


Atomic Mass on the Periodic TableAtomic Mass on the Periodic Table

1111

NaNa

22.9922.99

Atomic Numberor Protons

Symbol

Atomic Mass orProtons + neutrons


Atomic numberAtomic number

Atomic number =Atomic number =

# of Protons# of Protons

A=P=EA=P=E

M-A=NM-A=N


Mass NumberMass Number

The number The number

of of

protons protons andand neutronsneutrons

in an atomin an atom


Number of ElectronsNumber of Electrons

A balanced atom is neutral A balanced atom is neutral The net overall charge is zeroThe net overall charge is zero Number of protons = Number of electronsNumber of protons = Number of electrons Atomic number = Number of electronsAtomic number = Number of electrons


Identity & properties of Identity & properties of ElementsElements





Elements with similar properties are placed in the same group in the periodic table.

The stair-step line separates the elements into metals and nonmetals.


Metals & NonmetalsMetals & Nonmetals


ElementElement ProtoProtonsns

NeutronNeutronss

ElectronElectrons s

2 elements 2 elements with with similar similar propertiesproperties

Chlorine-35 1717 1818 1717 F and BrF and Br

Iron-56

Magnesium-24

Lead-208

Nitrogen-14

26 30 26 Ru and Os

12 1212 Ca and Sr

82 82126

7 7 7

Sn and Ge

P and As


Molecules & CompoundsMolecules & Compounds



MixturesMixturesCombination of two or more pure substances. Substances are mixed together but have not reacted to form any new molecules.

Example- Sugar (a compound) dissolves in water (a compound) to form a mixture. The molecules of sugar and water do not change chemically. They just become mixed together.

Organic CompoundsOrganic Compounds

Compounds that includes carbon along with Compounds that includes carbon along with other element(s) hydrogen, nitrogen, other element(s) hydrogen, nitrogen, phosphorous, and or sulfur.phosphorous, and or sulfur.

Nucleic Acid (DNA), Carbohydrates, Proteins, Nucleic Acid (DNA), Carbohydrates, Proteins, & Starch. & Starch.


Properties & ChangesProperties & Changes



Properties of matterPhysical properties – can be observed without changing the substance into a different substance.


Chemical PropertiesChemical Properties

Characteristics of a substance that are observed when it reacts (changes) to produce one or more different substances.

Example- Water can be changed into hydrogen gas and oxygen gas using an electric current. When water molecules change chemically into hydrogen gas and oxygen gas, we say that a chemical change has occurred. Hydrogen gas and oxygen gas each have a different set of properties.

Substances change into different substances through chemical reactions.


Chemical ReactionsChemical ReactionsSubstances change into other substances in chemical reactions.

The atoms in the original substance are rearranged. The bonds in the original substance may be broken and new bonds may be formed between different atoms. This produces one or more new substances that may be either pure elements or compounds.

The products of a chemical reaction always have difference chemical and physical properties than the original substance(s).

Evidence of a Chemical ReactionEvidence of a Chemical Reaction

a change in odor,a change in odor, a change in color, a change in color, a solid precipitate is formed, a solid precipitate is formed, a gas is formed, a gas is formed, there is either absorption (Endothermic) or there is either absorption (Endothermic) or

release (Exothermic) of heatrelease (Exothermic) of heat





Chemical EquationsChemical Equations


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STAAR Need to Know1 STAAR Reporting Category 1 Matter & Energy Middle School Science Science STAAR Need to Know