STAR Testing Review 8th Grade Science

STAR Testing Review 8th Grade Science

Structure of Matter

Periodic Table

Structure of Matter

Periodic Table

Solids, Liquids and GasesSolids, Liquids and Gases

STATES OF MATTER!!!STATES OF MATTER!!!

All matter is made of atoms and molecules, which we will call particles.

All particles vibrate or move because they have energy.

The state of matter they are in depends on how strongly they are attracted to each other.

All matter is made of atoms and molecules, which we will call particles.

All particles vibrate or move because they have energy.

The state of matter they are in depends on how strongly they are attracted to each other.

Matter that has defined shape and volume is considered to be solid.

Particles in a solid have high attraction for each other. The particles vibrate in place and don’t have enough energy to get away from each other

Two types of solids: Crystalline – particles in a repeating formation Amorphous – randomly oriented particles

Matter that has defined shape and volume is considered to be solid.

Particles in a solid have high attraction for each other. The particles vibrate in place and don’t have enough energy to get away from each other

Two types of solids: Crystalline – particles in a repeating formation Amorphous – randomly oriented particles

A solid has defined space and volume. It will not take the shape of the container unless energy is expended to make it a different shape.

A solid has defined space and volume. It will not take the shape of the container unless energy is expended to make it a different shape.

Liquids have defined volume but not defined shape

The particles in a liquid can slide past each other, and are less attracted to each other than in a solid.

Two properties of a liquid: Surface tension – the liquids tend to ball up and stick

together Viscosity – a measure of how well the liquid flows.

Water is low viscosity, molasses is high viscosity.

Liquids have defined volume but not defined shape

The particles in a liquid can slide past each other, and are less attracted to each other than in a solid.

Two properties of a liquid: Surface tension – the liquids tend to ball up and stick

together Viscosity – a measure of how well the liquid flows.

Water is low viscosity, molasses is high viscosity.

A liquid has defined volume but will take the shape of the container.

They have more energy than a solid

A liquid has defined volume but will take the shape of the container.

They have more energy than a solid

Gases have no defined shape or volume. They can be compressed by pressure and change their volume and will fill all the space they are given.

The particles in a gas are moving fast enough to break away from each other and each particle moves independently.

In a gas, there is empty space between particles. Pressure can effect all gases. High pressure means

that you have forced a large amount of gas particles in a small space – like inside a tire or basketball.

Gases have no defined shape or volume. They can be compressed by pressure and change their volume and will fill all the space they are given.

The particles in a gas are moving fast enough to break away from each other and each particle moves independently.

In a gas, there is empty space between particles. Pressure can effect all gases. High pressure means

that you have forced a large amount of gas particles in a small space – like inside a tire or basketball.

Gases

Phase Change!!!! Phase Change!!!!

Solid--> Liquid--> Gas-->and back! Solid--> Liquid--> Gas-->and back!

What IS phase change??What IS phase change??

Phase change is the change of the state (solid, liquid, gas) that the matter is in.

This change begins by either taking away energy or adding energy to the particles of matter.

These changes can start at any state and end at any state.

Phase change is the change of the state (solid, liquid, gas) that the matter is in.

This change begins by either taking away energy or adding energy to the particles of matter.

These changes can start at any state and end at any state.

Melting!Melting!

Melting involves ANY solid becoming a liquid.

Melting is ENDOTHERMIC- energy in the form of heat is ENTERING the reaction.

The molecules are gaining enough energy to break away from their rigid structure and move among the group.

Melting involves ANY solid becoming a liquid.

Melting is ENDOTHERMIC- energy in the form of heat is ENTERING the reaction.

The molecules are gaining enough energy to break away from their rigid structure and move among the group.

Melting!Melting!

Every substance has a “melting point”. The melting point is the temperature at

which the substance begins to melt. The melting point of a substance is a

physical property. **ALL substances have DIFFERENT

melting points! It’s not all the same as water!!!!!!!

Every substance has a “melting point”. The melting point is the temperature at

which the substance begins to melt. The melting point of a substance is a

physical property. **ALL substances have DIFFERENT

melting points! It’s not all the same as water!!!!!!!

FreezingFreezing

Freezing involves ANY liquid becoming a solid.

Freezing is an EXOTHERMIC reaction- energy is EXITING the reaction in the form of heat (heat is leaving).

The molecules are losing energy- and forced to stay in a rigid structure.

Freezing involves ANY liquid becoming a solid.

Freezing is an EXOTHERMIC reaction- energy is EXITING the reaction in the form of heat (heat is leaving).

The molecules are losing energy- and forced to stay in a rigid structure.

FreezingFreezing

Every Substance has a “freezing point” The freezing point is the temperature

where the substance begins to freeze or solidify.

The freezing point of a substance is a physical property and varies for each substance.

Every Substance has a “freezing point” The freezing point is the temperature

where the substance begins to freeze or solidify.

The freezing point of a substance is a physical property and varies for each substance.

CondensationCondensation

Condensation is when a gas becomes a liquid.

This is an EXOTHERMIC reaction- energy LEAVING in the form of heat.

The molecules are losing energy and become a group again after being totally independent.

Condensation is when a gas becomes a liquid.

This is an EXOTHERMIC reaction- energy LEAVING in the form of heat.

The molecules are losing energy and become a group again after being totally independent.

VaporizationVaporization

Evaporation is any liquid becoming a gas This reaction is ENDOTHERMIC-

energy is ENTERING in the form of heat!

The molecules are gaining SO much energy that they are becoming totally independent and fly away on their own!

Evaporation is any liquid becoming a gas This reaction is ENDOTHERMIC-

energy is ENTERING in the form of heat!

The molecules are gaining SO much energy that they are becoming totally independent and fly away on their own!

VaporizationVaporization

There are two types: Boiling Evaporation

There are two types: Boiling Evaporation

BoilingBoiling

Boiling is… a relatively quick change from a liquid to a gas Occurs by adding a lot of heat all at once Happens at a specific temperature The change happens within the ENTIRE fluid-

all molecules are being affected.

Boiling is… a relatively quick change from a liquid to a gas Occurs by adding a lot of heat all at once Happens at a specific temperature The change happens within the ENTIRE fluid-

all molecules are being affected.

EvaporationEvaporation

Evaporation is… A relatively slow process Occurs overtime from gas particles crashing

onto the surface of the liquid and passing on their energy to the liquid molecules.

No specific temperature associated with this change (can happen at room temp!)

Happens only on the surface of the liquid.

Evaporation is… A relatively slow process Occurs overtime from gas particles crashing

onto the surface of the liquid and passing on their energy to the liquid molecules.

No specific temperature associated with this change (can happen at room temp!)

Happens only on the surface of the liquid.

Particles in a gas state are not bound to each other and have the most energy.

Particles in a gas state are not bound to each other and have the most energy.

Example of a Gas

The parts of an AtomThe parts of an Atom

The atomThe atom

An Atom: The most basic unit of matter. An atom has a dense nucleus and a cloud of

negatively charged electrons around it. If matter is what everything is made of, and

matter is made of atoms… Then, everything is really made of atoms!

An Atom: The most basic unit of matter. An atom has a dense nucleus and a cloud of

negatively charged electrons around it. If matter is what everything is made of, and

matter is made of atoms… Then, everything is really made of atoms!

The Parts:The Parts: Electron: A subatomic particle with a negative

electrical charge. (no mass) Nucleus: The dense center of an atom

containing protons and neutrons. A Proton: A subatomic particle within the

nucleus of an atom that has a positive charge. A Neutron: A subatomic particle within the

nucleus of an atom that has a neutral charge.

Electron: A subatomic particle with a negative electrical charge. (no mass)

Nucleus: The dense center of an atom containing protons and neutrons.

A Proton: A subatomic particle within the nucleus of an atom that has a positive charge.

A Neutron: A subatomic particle within the nucleus of an atom that has a neutral charge.

Energy LevelEnergy Level

The energy level of an atom is as follows: 2,8,8

The first shell has two electrons The second shell has 8 electrons The third shell has 8 electrons

MEMORIZE: 2,8,8!!!!!!!!!!

The energy level of an atom is as follows: 2,8,8

The first shell has two electrons The second shell has 8 electrons The third shell has 8 electrons

MEMORIZE: 2,8,8!!!!!!!!!!

Atomic NumberAtomic Number

The atomic number is the number mainly associated with the element and represents the number of protons present in the atom.

The atomic number is the number mainly associated with the element and represents the number of protons present in the atom.

Mass NumberMass Number The total number of

protons and neutrons. The mass of an atom comes

from the protons and neutrons. Therefore, the mass includes

the masses of each added together.

This number can be found at the bottom, typically.

The total number of protons and neutrons.

The mass of an atom comes from the protons and neutrons. Therefore, the mass includes

the masses of each added together.

This number can be found at the bottom, typically.

Mass Number

ElementElement Each of these are ELEMENTS!!!

When you put them together, they become something different…

Each of these are ELEMENTS!!!

When you put them together, they become something different…

Compounds!Compounds!

Remember that compounds are merely the result of combining two or more elements.

H2O is a compound! NaCl is a compound!

REMEMBER- compounds have different properties than the elements they are made of when alone. Hence why table salt (NaCl) doesn’t blow up

Remember that compounds are merely the result of combining two or more elements.

H2O is a compound! NaCl is a compound!

REMEMBER- compounds have different properties than the elements they are made of when alone. Hence why table salt (NaCl) doesn’t blow up

How can you identify Elements?How can you identify Elements?

What are the elements in the following compounds? H2O

NaCl CO2

What are the elements in the following compounds? H2O

NaCl CO2

Periodic Table!! Periodic Table!!

Remember that beautiful display of elements?

It’s time to remember how to use it!

Remember that beautiful display of elements?

It’s time to remember how to use it!

Time to test your knowledge! Time to test your knowledge!

How many groups are there? Which group number are the noble (inert) gases? Why are the noble gases important? Where are the metals located? Where are the semi-metals? Where are the Alkali metals located? Where are the Alkaline Earth metals located?

How many groups are there? Which group number are the noble (inert) gases? Why are the noble gases important? Where are the metals located? Where are the semi-metals? Where are the Alkali metals located? Where are the Alkaline Earth metals located?

Review of Chemical BondingReview of Chemical Bonding

Ionic, Covalent, MetallicIonic, Covalent, Metallic

Ionic BondsIonic Bonds

Ionic Bonds occur between metals and non-metals.

Metals always lose their extra valence electrons and non-metals always try to gain extra valence electrons.

Metals become positive ions and non-metals become negative ions.

Ionic Bonds occur between metals and non-metals.

Metals always lose their extra valence electrons and non-metals always try to gain extra valence electrons.

Metals become positive ions and non-metals become negative ions.

Ionic BondsIonic Bonds

Properties of Ionic Bonds: Brittle (breaks easily) Extremely high melting and boiling points Conduct electricity Form between ions (metals & non-metals)

Properties of Ionic Bonds: Brittle (breaks easily) Extremely high melting and boiling points Conduct electricity Form between ions (metals & non-metals)

Covalent BondsCovalent Bonds

Covalent bonds occur between non-metals and non-metals

Since non-metals are always trying to find extra electrons rather than get rid of them, Covalent bonds always share their electrons (how nice of them!)

Covalent bonds occur between non-metals and non-metals

Since non-metals are always trying to find extra electrons rather than get rid of them, Covalent bonds always share their electrons (how nice of them!)

Covalent BondsCovalent Bonds

Properties of Covalent Bonds Malleable (can be formed/manipulated) Low melting and boiling points Do not conduct electricity or heat

Properties of Covalent Bonds Malleable (can be formed/manipulated) Low melting and boiling points Do not conduct electricity or heat