Ips Ch. 17

Unit 5: The AtomUnit 5: The Atom

Chapter 17: Atoms and the Chapter 17: Atoms and the Periodic TablePeriodic Table

17.1 – Elements Contain a 17.1 – Elements Contain a Single Kind of AtomSingle Kind of Atom

Substances result from how atoms Substances result from how atoms combine.combine.

To date, we know of slightly more To date, we know of slightly more than 100 distinct atoms.than 100 distinct atoms.

90 atoms are found in nature.90 atoms are found in nature. The rest are created in a laboratory.The rest are created in a laboratory.

17.1 Elements Contain a 17.1 Elements Contain a Single Kind of AtomSingle Kind of Atom

Element Element – Any – Any material that is material that is made up of only made up of only one type of atom.one type of atom.

Periodic TablePeriodic Table – – Lists all the known Lists all the known elements.elements.


Each element is Each element is designated by its designated by its atomic symbol.atomic symbol.

The atomic symbol The atomic symbol comes from the comes from the letters of the letters of the element’s name.element’s name.

Sometimes the Sometimes the atomic symbol is atomic symbol is derived from the derived from the element’s Latin element’s Latin name.name.


Only the first letter of the atomic Only the first letter of the atomic symbol is capitalized.symbol is capitalized.

Hydrogen makes up more than 90% Hydrogen makes up more than 90% of all atoms.of all atoms.

Hydrogen is light and has a simple Hydrogen is light and has a simple structure.structure.

Atoms combine to form matter that Atoms combine to form matter that is living and nonliving.is living and nonliving.


Atoms are so small that they can’t be Atoms are so small that they can’t be seen with visible light.seen with visible light.

Brownian MotionBrownian Motion – Perpetual jiggling – Perpetual jiggling of particles that result from collisions of particles that result from collisions between visible particles and between visible particles and invisible atoms. (Robert Brown – invisible atoms. (Robert Brown – 1827)1827)


Atoms are made of Atoms are made of smaller, subatomic smaller, subatomic particles: electrons, particles: electrons, protons, and neutrons.protons, and neutrons.

Atoms differ by the Atoms differ by the number of these number of these particles.particles.

Protons and neutrons Protons and neutrons bind together to from bind together to from the larger, atomic the larger, atomic nucleus.nucleus.


Atomic NucleusAtomic Nucleus – Contains most of – Contains most of the atom’s mass.the atom’s mass.

ElectronsElectrons – Surrounds the nucleus. – Surrounds the nucleus.

17.2 – Atoms Are Mostly Empty 17.2 – Atoms Are Mostly Empty SpaceSpace

Electrical RepulsionElectrical Repulsion - In the outer - In the outer regions of any atom lie the electrons, regions of any atom lie the electrons, which repel electrons of other atoms.which repel electrons of other atoms.

17.3 – The Atomic Nucleus Is 17.3 – The Atomic Nucleus Is Made of Protons and NeutronsMade of Protons and Neutrons

ProtonProton – A particle – A particle found in the atomic found in the atomic nucleus and carries a nucleus and carries a positive charge.positive charge.

A proton is 2,000 A proton is 2,000 times as massive as times as massive as the electron.the electron.

The proton and The proton and electron have the electron have the same quantity of same quantity of charge, but the charge, but the charges are opposite.charges are opposite.


The # of protons in The # of protons in the nucleus is equal the nucleus is equal to the # of to the # of electrons whirling electrons whirling about the nucleus.about the nucleus.

They cancel each They cancel each other out!other out!

The atom has an The atom has an overall electric overall electric charge of zero. charge of zero. (electrically neutral)(electrically neutral)


Atomic NumberAtomic Number - - The number of The number of protons contained protons contained in each atomic in each atomic nucleus.nucleus.

NeutronNeutron – A nuclear – A nuclear particle with about particle with about the same mass as the same mass as the proton, but with the proton, but with no electric charge.no electric charge.


Subatomic ParticlesSubatomic Particles Mass ComparedMass Compared

ParticleParticle Charge Charge to electronto electron Actual Mass* (kg)Actual Mass* (kg)______________________________________________________________________________________________________________________________________________

Electron -1Electron -1 1 1 9.11 x x10 9.11 x x10-31+-31+

ProtonProton +1 +1 1836 1836 1.673 x 101.673 x 10-27-27NNNNNucleonsNucleons

NeutronNeutron 0 1841 1.675 x x10 0 1841 1.675 x x10 -27-27

______________________________________________________________________________________________________________________________________________ *Not measured directly but calculated from experimental data.*Not measured directly but calculated from experimental data. + 9.11 x 10+ 9.11 x 10-31-31 kg – 0.000000000000000000000000000000911 kg – 0.000000000000000000000000000000911


NucleonsNucleons – Protons and Neutrons. – Protons and Neutrons. # of protons for an atom is definite, # of protons for an atom is definite,

but 3 of neutrons are not.but 3 of neutrons are not. IsotopesIsotopes – Atoms of the same – Atoms of the same

element that contain different element that contain different numbers of neutrons.numbers of neutrons.

17.4 – Protons and Neutrons 17.4 – Protons and Neutrons Determine Mass Number and Determine Mass Number and

Atomic MassAtomic Mass Mass NumberMass Number – The total number of – The total number of

protons and neutrons they contain.protons and neutrons they contain. Mass numbers are how we tell Mass numbers are how we tell

isotopes apart.isotopes apart. Another option is to write the mass Another option is to write the mass

number as a superscript and the number as a superscript and the atomic number as a subscript.atomic number as a subscript.

17.4 Protons and Neutrons Determine 17.4 Protons and Neutrons Determine Mass Number and Atomic MassMass Number and Atomic Mass


Atomic MassAtomic Mass Mass number – atomic number = Mass number – atomic number =

number of neutrons.number of neutrons. Isotopes can only be distinguished by Isotopes can only be distinguished by

mass, not by electrical means.mass, not by electrical means. Atomic MassAtomic Mass – The total mass of an – The total mass of an

atom. (electrons, proton, and neutrons)atom. (electrons, proton, and neutrons) AmuAmu – The atomic mass unit. – The atomic mass unit. One amu is slightly less than the mass One amu is slightly less than the mass

of a single proton.of a single proton.


Atomic MassAtomic Mass

17.5 Elements Are Organized 17.5 Elements Are Organized in the Periodic Table by Their in the Periodic Table by Their

PropertiesProperties


PropertiesProperties MetalsMetals - Elements that are - Elements that are

shiny, opaque, and good shiny, opaque, and good conductors of electricity conductors of electricity and heat.and heat.

MalleableMalleable – Can be – Can be hammered into different hammered into different shapes or bent w/o shapes or bent w/o breaking.breaking.

DuctileDuctile – Can be drawn – Can be drawn into wires.into wires.

Hydrogen is a liquid metal Hydrogen is a liquid metal at high pressures. at high pressures. Normally it is a nonmetallic Normally it is a nonmetallic gas.gas.


PropertiesProperties NonmetalsNonmetals – Very poor – Very poor

conductors of conductors of electricity and heat, electricity and heat, may be transparent.may be transparent.

Not malleable nor Not malleable nor ductile.ductile.

They are brittle and They are brittle and shatter when shatter when hammered.hammered.

Some are solid, some Some are solid, some liquid, and some gas.liquid, and some gas.


PropertiesProperties MetaloidsMetaloids – Have – Have

metallic and metallic and nonmetallic nonmetallic characteristics.characteristics.

Weak conductors Weak conductors of electricity.of electricity.

Boron, B; silicon, Boron, B; silicon, Si; germanium, Ge; Si; germanium, Ge; arsenic, As; tin, Sn; arsenic, As; tin, Sn; and antimony, Sb.and antimony, Sb.

17.6 A Period Is a Horizontal 17.6 A Period Is a Horizontal Row, a Group Is a Vertical Row, a Group Is a Vertical

ColumnColumn

17.6 A Period Is a Horizontal 17.6 A Period Is a Horizontal Row, a Group Is a Vertical Row, a Group Is a Vertical

ColumnColumn PeriodPeriod – Each horizontal row. (There – Each horizontal row. (There

are 7 periods)are 7 periods) GroupGroup – (Family) Each vertical – (Family) Each vertical

column. (There are 18 groups)column. (There are 18 groups) Periodic TrendPeriodic Trend – How the properties – How the properties

of elements gradually change across of elements gradually change across a period.a period.

Periodic TrendPeriodic Trend

Atomic size becomes smaller as you Atomic size becomes smaller as you move from left to right.move from left to right.

A vertical column share very similar A vertical column share very similar properties. (family)properties. (family)

Common names for various Common names for various groups of elementsgroups of elements

Alkali Metals – Group 1 elementsAlkali Metals – Group 1 elements Alkaline-earth metals – Group 2 Alkaline-earth metals – Group 2

elementselements Transition metals – Groups 3 – 12Transition metals – Groups 3 – 12 Chalcogens – Group 16Chalcogens – Group 16 Halogens – Group 17Halogens – Group 17 Noble gases – Group 18Noble gases – Group 18

Inner Transition MetalsInner Transition Metals

58 – 71 and 90 – 103 Subsets of the 58 – 71 and 90 – 103 Subsets of the sixth period and seventh period.sixth period and seventh period.

66thth period inner transition metals are period inner transition metals are called lanthanides.called lanthanides.

77thth period inner transition metals are period inner transition metals are called actinides.called actinides.

Ips Ch. 17

Technology

Transcript of Ips Ch. 17