Properties of MatterProperties of Matter

ElementElement

A pure substance that A pure substance that cannot be broken cannot be broken down into simpler down into simpler substances by substances by ordinary chemical ordinary chemical means.means.

Sulfur

AtomAtomThe smallest unit of an The smallest unit of an

element that still has element that still has the properties of that the properties of that element.element.

Each element on the Each element on the periodic table is periodic table is composed of atomscomposed of atoms

of only one kindof only one kind..

CompoundCompoundA substance made up A substance made up

of atoms of more of atoms of more than one element than one element bonded together.bonded together.

Ex: HEx: H22O has different O has different

properties than H or properties than H or O alone.O alone.

Water (liquid)

Oxygen (gas)

MoleculeMoleculeThe smallest unit of a The smallest unit of a

substance that still has substance that still has all of the properties of all of the properties of that substance.that substance.

A molecule can be A molecule can be composed of atoms of composed of atoms of a single element (Na single element (N22), ),

or be a compound or be a compound (H(H22O).O).

Nitrogen

Water

Chemical FormulaChemical FormulaThe chemical symbols and The chemical symbols and

numbers indicating the numbers indicating the numbers of atoms numbers of atoms contained in the basic contained in the basic unit of a substance.unit of a substance.

Ex: A water molecule Ex: A water molecule (H(H22O) contains two O) contains two

hydrogen atoms and one hydrogen atoms and one oxygen atom.oxygen atom.

Chemical FormulaChemical Formula

A glucose molecule A glucose molecule (C(C66HH1212OO66) contains 6 ) contains 6

carbon atoms, 12 carbon atoms, 12 hydrogen atoms, and hydrogen atoms, and 6 oxygen atoms.6 oxygen atoms.

States of MatterStates of Matter

States of MatterStates of Matter

SolidSolid- A form of - A form of matter with a definite matter with a definite volume and a volume and a definite shape.definite shape.

States of MatterStates of Matter

LiquidLiquid- A form of - A form of matter that has a matter that has a definite volume but definite volume but no definite shape.no definite shape.

States of MatterStates of Matter

GasGas- A form of matter - A form of matter that has no definite that has no definite volume and no volume and no definite shape.definite shape.

Melting PointMelting Point

The temperature at The temperature at which a solid which a solid becomes a liquid.becomes a liquid.(0°C for water)(0°C for water)

Boiling PointBoiling Point

The temperature at The temperature at which a liquid which a liquid becomes a gas.becomes a gas.

(100(100°C for water)°C for water)

How Do Solids Differ From Liquids?How Do Solids Differ From Liquids?

Particles are closer together. (Greater density)Particles are closer together. (Greater density)

Particles have less energy. (Moving slower)Particles have less energy. (Moving slower)

Attractive forces between molecules are Attractive forces between molecules are stronger.stronger.

How Do Liquids Differ From Gases?How Do Liquids Differ From Gases?

Particles are closer together.Particles are closer together.

Particles have less energy.Particles have less energy.

Attractive forces between molecules are Attractive forces between molecules are stronger.stronger.

Early Ideas About The AtomEarly Ideas About The Atom

Democritus (Greek)Democritus (Greek)- - Proposed the idea that Proposed the idea that all matter is composed all matter is composed of very small particles of very small particles that could not be that could not be divided. Atom- divided. Atom- “indivisible”“indivisible”

Early Ideas About The AtomEarly Ideas About The Atom

John Dalton (b. 1766)John Dalton (b. 1766)--

Proposed the idea that Proposed the idea that all matter is all matter is composed of small composed of small particles that particles that combine to form combine to form molecules.molecules.

Dalton’s Atomic TheoryDalton’s Atomic Theory

1.1. Every element is made up of tiny particles Every element is made up of tiny particles called atoms that cannot be broken down into called atoms that cannot be broken down into simpler particles.simpler particles.

2.2. Atoms of the same element are exactly alike.Atoms of the same element are exactly alike.

3.3. Atoms of different elements can join to form Atoms of different elements can join to form molecules.molecules.

Early Ideas About The AtomEarly Ideas About The Atom

J.J. Thomson (1856-J.J. Thomson (1856-1940)1940)- Proposed the - Proposed the idea that atoms are idea that atoms are composed of smaller composed of smaller charged particles that charged particles that hold the atom hold the atom together. Opposite together. Opposite charges attract.charges attract.

Early Ideas About The AtomEarly Ideas About The Atom

Ernest Rutherford Ernest Rutherford

(1871-1937)(1871-1937)- Conducted - Conducted an experiment that an experiment that provided evidence for provided evidence for the existence of a the existence of a positively charged positively charged nucleus inside of atoms. nucleus inside of atoms. The mass of an atom is The mass of an atom is concentrated inside the concentrated inside the nucleus.nucleus.

Early Ideas About The AtomEarly Ideas About The Atom

Niels Bohr (1885-Niels Bohr (1885-1962)1962)- Proposed the - Proposed the idea that negatively idea that negatively charged electrons are charged electrons are located in orbits or located in orbits or energy levels around energy levels around the nucleus.the nucleus.

Sub-atomic ParticlesSub-atomic ParticlesNucleusNucleus- The center of an atom. Made up of - The center of an atom. Made up of

protons and neutrons.protons and neutrons.

ProtonProton- A sub-atomic particle in the nucleus of - A sub-atomic particle in the nucleus of an atom. Protons have a positive electrical an atom. Protons have a positive electrical charge (+) and a mass of 1 atomic mass unit charge (+) and a mass of 1 atomic mass unit (amu).(amu).

Sub-atomic ParticlesSub-atomic ParticlesNeutronNeutron- A sub-atomic particle in the nucleus of - A sub-atomic particle in the nucleus of

an atom. Neutrons are neutral, meaning that an atom. Neutrons are neutral, meaning that they have no charge, and a mass of 1 amu.they have no charge, and a mass of 1 amu.

ElectronElectron- A sub-atomic particle orbiting outside - A sub-atomic particle orbiting outside the nucleus of an atom. Electrons have a the nucleus of an atom. Electrons have a negative electrical charge and no mass.negative electrical charge and no mass.

Atoms in their most stable state have an equal Atoms in their most stable state have an equal number of protons, neutrons and electrons.number of protons, neutrons and electrons.

MassMass ChargeCharge LocationLocation

ElectronsElectrons ~0~0 -1-1Orbits in Orbits in shells around shells around nucleusnucleus

ProtonsProtons 1amu1amu +1+1 NucleusNucleus

NeutronsNeutrons 1amu1amu NucleusNucleus

Sub-atomic ParticlesSub-atomic Particles

Atomic NumberAtomic Number

The number of The number of protons in the protons in the nucleus of an nucleus of an atom.atom.

Atomic MassAtomic Mass

The number of The number of protons and protons and neutrons in the neutrons in the nucleus of an nucleus of an atom.atom.

Valence ElectronValence Electron

An electron in the An electron in the outermost energy outermost energy level of an atom.level of an atom.

Which Element?Which Element?(2,8,6)

Atoms are stable with 8 valence electrons

IonIon

An atom or group An atom or group of atoms that has of atoms that has lost or gained lost or gained electrons and is electrons and is left with a net left with a net electric charge.electric charge.

Chemical BondingChemical BondingThe attractive force that holds atoms together The attractive force that holds atoms together in molecules and compounds.in molecules and compounds.

Ionic BondIonic Bond

A chemical bond in which electrons are A chemical bond in which electrons are exchanged between atoms.exchanged between atoms.

Ex: LiEx: Li++FF−−

Crystal LatticeCrystal Lattice

An orderly, three dimensional structure An orderly, three dimensional structure produced by ions in an ionic compound.produced by ions in an ionic compound.

Covalent BondCovalent Bond

A chemical bond in which electrons are A chemical bond in which electrons are shared between atoms.shared between atoms.

Ex: OEx: O22

MoleculeMolecule

A neutral group of A neutral group of atoms that are atoms that are joined together by joined together by one or more one or more covalent bonds.covalent bonds.

Polar Covalent BondPolar Covalent Bond

A covalent bond in which the electrons A covalent bond in which the electrons are not shared equally.are not shared equally.

Ex: HEx: H22OO

Water MoleculeWater Molecule

PolarityPolarity

Non-polar Covalent BondNon-polar Covalent Bond

A covalent bond in A covalent bond in which the which the electrons are electrons are shared equally.shared equally.

Ex: OEx: O22

Metallic BondMetallic Bond

The attraction between The attraction between a positive ion and the a positive ion and the “sea of electrons” “sea of electrons” that surrounds it.that surrounds it.