Periodic Table - 2 An element is a type of atom that is distinguished by its atomic number; An element is a type of atom that is distinguished by its atomic.

Periodic Table - 2Periodic Table - 2 An element is a type of An element is a type of atomatom that is that is

distinguished by its distinguished by its atomic numberatomic number; ;

The number above the letter stands The number above the letter stands for 3 things in a neutral atom for 3 things in a neutral atom (atomic number, number of protons (atomic number, number of protons and number of electrons)and number of electrons)

CompoundsCompounds chemical chemical

compoundcompound is a is a substancesubstance consisting of two consisting of two or more different or more different elementselements chemically bondchemically bondeded together in a together in a fixed proportion fixed proportion by by massmass

HH2 2 is not a is not a compound since compound since it is made up of it is made up of only 1 element.only 1 element.

NaCl (salt) is a NaCl (salt) is a compound.compound.

MoleculesMolecules A moleculeA molecule is is

defined as a defined as a sufficiently stable sufficiently stable electricallyelectrically neutral group of neutral group of at least two at least two atomsatoms in a definite in a definite arrangement held arrangement held together by together by strong strong chemical bondschemical bonds

It may consist It may consist (made up) of atoms (made up) of atoms of the same of the same chemical elementchemical element, , as with as with oxygenoxygen (O(O22), or of different ), or of different elements, as with elements, as with waterwater (H (H22O).O).

When 2 elements When 2 elements from the right side from the right side of the Periodic of the Periodic table get together, table get together, it is called a it is called a molecule molecule

MixturesMixtures Mixtures can be homogeneous or Mixtures can be homogeneous or

heterogeneous.heterogeneous.

Homogeneous = Looks same Homogeneous = Looks same throughout (solutions like – salt waterthroughout (solutions like – salt water

Heterogeneous = Looks different Heterogeneous = Looks different throughout (granola cereal/salad)throughout (granola cereal/salad)

SolutionsSolutions A A solutionsolution is a is a

homogeneoushomogeneous mixturemixture composed of two or more composed of two or more substances. substances.

In such a mixture, a In such a mixture, a solutesolute is dissolved in another is dissolved in another substance, known as a substance, known as a solventsolvent. .

common examples ( common examples ( saltsalt or or sugarsugar dissolved in dissolved in waterwater, a , a liquidliquid. . GasesGases may may dissolvedissolve in liquids also in liquids also carbon dioxidecarbon dioxide or or oxygenoxygen in water. in water.

ColloidColloid A A colloidcolloid is a type of is a type of

mechanical mechanical mixturemixture where one substance is where one substance is dispersed evenly dispersed evenly throughout another. A throughout another. A colloidal system may be colloidal system may be solidsolid, , liquidliquid, or , or gaseousgaseous..

fogfog, , mistmist, , milkmilk, , mayonnaisemayonnaise, hand cream, , hand cream, whipped creamwhipped cream, , butterbutter, , gelatingelatin, , jellyjelly, , cheesecheese, , opalopal, , paintpaint, , pigmented inkpigmented ink, , smokesmoke, air , air particulatesparticulates

SuspensionSuspension A A suspensionsuspension is a is a

heterogenousheterogenous fluid containing fluid containing solidsolid particles that are particles that are sufficiently large for sufficiently large for sedimentationsedimentation

MudMud or muddy water, is where or muddy water, is where soilsoil, , clayclay, or , or siltsilt particles in particles in waterwater

FlourFlour suspended in water suspended in water FogFog water suspended in air. water suspended in air. Paint Paint Chalk powder suspended in Chalk powder suspended in

water. water. Dust particles suspended in air. Dust particles suspended in air.

Period/RowPeriod/Row Another word Another word

for rows are for rows are periods. periods.

The periods The periods (rows) go side to (rows) go side to side on a side on a Periodic Table.Periodic Table.

Group/FamilyGroup/Family There are 18 There are 18

groups on the groups on the Periodic Table. Periodic Table.

Groups are also Groups are also called families called families or columns…….or columns…….(goes up and (goes up and down).down).

Groups (families) Groups (families) share share characteristics just characteristics just like you share like you share characteristics with characteristics with your family. They your family. They bond the same way bond the same way since they have the since they have the same amount of same amount of valence electrons.valence electrons.

Periodic TablePeriodic Table The modern periodic The modern periodic

table arrangement table arrangement was made by a was made by a RussianRussian chemistchemist named named Dmitri MendeleevDmitri Mendeleev in in 1869.1869.

The current standard The current standard table contains 117 table contains 117 confirmed elements confirmed elements as of as of January 27January 27, , 20082008

The elements on The elements on the Periodic the Periodic table are in table are in order of order of increasing increasing atomic number.atomic number.

ChargesCharges Neutral atoms have Neutral atoms have

no charge.no charge.

When atoms are not When atoms are not neutral, they have a neutral, they have a charge.charge.

When atoms have a When atoms have a charge, they bond or charge, they bond or get together with get together with other atoms to go to other atoms to go to a neutral state.a neutral state.

Noble gases are Noble gases are always neutral. always neutral. They do not have They do not have charges. They charges. They do not bond with do not bond with other elements. other elements. They are happy They are happy by themselves.by themselves.

Alkali MetalsAlkali Metals

Group 1 is the alkali metals (+1 Group 1 is the alkali metals (+1 Charge)Charge)

(Lithium, Sodium, Potassium, (Lithium, Sodium, Potassium, Rubidium, Cesium, Francium)Rubidium, Cesium, Francium)