Bellwork Monday, 10/28 To the right is a label from a popular food item. Name five elements that are found on this food label.

CHEMICAL NAMES AND FORMULAS CHEMISTY I CHAPTER 6 CHEMICAL NAMES AND FORMULAS

Molecule- the smallest electrically neutral unit of a substance that still has the properties of that substance -made up of two or more atoms that act as a unit Ex. CH4 O2 H2O CO2 O3

Molecular compound- -usually composed of molecules -Have low melting & boiling points -Are usually made up of two or more NONMETALS Sugar, a compound made of carbon, hydrogen and oxygen, melts easily in a hot pan.

Which of the following is molecular and which is ionic? NaCl H2O CaCO3 CO Al2Cl3 CF4 O3

diatomic molecule –consists of two atoms of the same element (O2 and H2)

triatomic molecule- contain three atoms of the same element (O3, ozone)

Molecular Compounds and Acids Binary Molecular Compounds When naming binary molecular compounds, prefixes are used to tell how many of each atom is in the formula. CO2 carbon dioxide N2O4 dinitrogen tetroxide

The prefix mono- is never used with the first element The prefix mono- is never used with the first element. The prefix list in on page 159. 1- 6- 2- 7- 3- 8- 4- 9- 5- 10- hexa mono di hepta tri octa nona tetra penta deca

Example: PBr3 ICl3 P2O5 Sulfur hexafluoride tetraarsenic hexoxide phosphorous tribromide iodine trichloride diphosphorous pentoxide SF6 As4O6

Acids and Bases hydrochloric acid sulfuric acid nitric acid You need to know the names and formulas of these most common acids: HCl H2SO4 HNO3 HC2H3O2 H3PO4 hydrochloric acid sulfuric acid nitric acid acetic acid phosphoric acid

Covalent Two Nonmetals Example: Rule: Use _________ to tell the _________ of each element. _____________ Note: A prefix is NOT needed on the first element if there is only 1. 1= 6= 2= 7= 3= 8= 4= 9= 5= 10= Acids: contain the element ________ at the left of the formula Need to know: HCl: H2SO4: HNO3: HC2H3O2: H3PO4:

Bellwork, Tuesday How many protons, neutrons and electrons are in this atom? Based on what you know about the charge of a proton and an electron, what is the overall charge of this atom? What element is this atom? Red =protons Yellow=neutrons Black=electrons

Ions- atoms or groups of atoms that have a positive or negative charge Ions- atoms or groups of atoms that have a positive or negative charge. Ions are formed when one or more electrons are lost or gained.

Let’s Practice! Sodium loses an electron Na  __________ Magnesium loses two electrons Mg  __________ Chlorine gains one electron Cl  __________ Phosphorus gains three electrons P  __________

We are positive about metal cats! Cation- -positively charged ion -electrons were lost -metals tend to form cations -name of monatomic cation is the same as the element We are positive about metal cats!

Examples: Na  Na+ + e- Ca  Ca2+ + 2e- Fe  Fe3+ + 3e-

We feel negatively about ants! Anion - negatively charged ion -electrons were gained -nonmetals tend to form anions -name of monatomic anion ends in –ide We feel negatively about ants! Examples:

Ionic compound- -composed of cations and anions -usually metal & nonmetal -electrically neutral -mostly solids at room temperature -high melting points -the more positive element always comes first -Ex NaCl, NaF, CaCl2

Monatomic Ions The charge of a monatomic ion can often be determined by the element’s position on the periodic table: Group 1A: 1+ Ex. Na+ Group 2A: 2+ Ex. Ca2+ Group 3A: 3+ Ex. Al3+ Group 5A: 3- Ex. N3- Group 6A: 2- Ex. O2- Group 7A: 1- Ex. F- See Table 6-2 (pg 143)

The noble gasses have no charge and are inert Alkali metals have a charge of +1 The halogens have a charge of -1 The oxygen family has a charge of -2 The carbon family has a charge of + or -4 The boron family has a charge of +3 Alkaline Earth metals have a charge of +2 The nitrogen family has a charge of -3 Transition metal charges will need to be memorized!

Elements in Group 0 (8) do not form ions Elements in Group 0 (8) do not form ions. Elements in Group 4 rarely form ions. They tend to react by sharing electrons (forming covalent compounds) instead of transferring electrons. Group 8 Electron configuration = s2p6 Group 4 Electron configuration = s2p2

What causes the charges for each group on the periodic table? The charges indicate how many electrons an atom will gain or lose. If it loses 2, the charge will be +2. If it gains 2, the charge will be -2. Remember that electrons are NEGATIVE!

Octet Rule and Stability The goal of an atom is to become stable. An atom will gain, lose, or share electrons in order for that stability to be attained. Stability is determined by the octet rule: Most atoms want 8 valence (outer shell) electrons in order to become stable.

Ex: Potassium (and all of group 1) has 1 valence electron, so it will lose 1 electron making its charge +1. Remember that electrons are NEGATIVE!

Examples: O P F Na Mg Al Sr 2- 3- 1- 1+ 2+ 3+ 2+

Transition Metal ions (See Table 6-3 pg 144): Most transition metals form more than one ion. They are stable losing varying numbers of electrons. The possible charges must be memorized.

Exceptions: Zinc and Cadmium will always be 2+ and Silver will always be 1+.

What is the formula for the following transition metals as ions? Copper (I) Iron (III) Lead (II) Manganese (III)

The mercury(I) ion is unique The mercury(I) ion is unique. It only exists in pairs of mercury(I) ions (like Siamese twins). Its symbol is Hg22+.

Quick Check Quiz: Have you been studying your ions Quick Check Quiz: Have you been studying your ions? sodium _______ chromous ________ selenide _______ tin(IV) ________ Na+ Cr2+ Se2- Sn4+

Rubidium loses one electron _____ Silver loses one electron _____ Wednesday Bellwork Write the ion that forms. Rubidium loses one electron _____ Silver loses one electron _____ Arsenic gains three electrons _____ Sulfur gains two electrons _____ Lithium loses one electron _____

Wednesday Bellwork Name the following compounds or write the formulas, as appropriate. CCl4 P4O10 N2O7 XeF4

Thursday Bellwork Practice your ions! Write the symbol and charge for the following ions. Nitride Oxide Magnesium ion Rubidium ion Fluoride

Friday Bellwork Match the following ions with their names. ___NO3- A. nitride ___CN- B. silver ion ___Ag+ C. cyanide ___NH4+ D. ammonium ___N3- E. chloride ___Cl- F. nitrate

Polyatomic Ions (Table 6-4, pg 147): -tightly bound groups of atoms that behave as a unit and carry a charge -atoms are bound together by shared electrons

The only positively charged polyatomic ion that we need to memorize is ammonium, NH4+.

Ions that end in –ite or –ate contain oxygen Ions that end in –ite or –ate contain oxygen. In a series such as sulfate and sulfite, the –ite ending has one less oxygen than the –ate ending. Sulfite SO32- Sulfate SO42-

SO32- sulfite SO42- sulfate NO2- nitrite NO3- nitrate EXAMPLES SO32- sulfite SO42- sulfate NO2- nitrite NO3- nitrate

Writing Formulas Binary compounds- 2 elements Binary ionic compounds- 1 metal + 1 nonmetal Binary molecular compounds- 2 nonmetals

Examples: NaCl NaF nonmetal metal CaCl2 **The more positive element (metal) always comes first.

When naming ionic compounds, simply name the ions as they appear in the formula. When naming ionic compounds containing a transition metal, include the Roman numeral representing the charge.

Ionic Metal and Nonmetal _____VALENT METAL means: _____________ Metals in group _____, _______, & these 4: __________________ Ex: Rule: Name the __________ then the __________ ending in ________. _____VALENT METAL means: ___________________________ Located in ________ & under the __________________. Same as mono- BUT use a ______________ to tell the metal’s __________.

Contains a polyatomic ion: Ionic Contains a polyatomic ion: Ex: Rule: Follow the same mono- or multi- valent metal rules; use the polyatomic ion’s name.

Example: aluminum chloride AlCl3 KBr FeCl2 FeCl3 potassium bromide iron(II) chloride iron(III) chloride

When writing the formula for an ionic compound, the charges of the ions must cancel out to give the compound a neutral charge.

Example: sodium chloride Na+ Cl- 1 1 Na1Cl1 = NaCl

magnesium iodide Mg2+ I- 2 1 Mg1I2 = MgI2

magnesium nitride Mg 2+ N3- 2 3 Mg3N2

strontium selenide Sr2+ Se2- 2 2 = Sr2Se2 SrSe

rubidium iodide Rb+ I- RbI aluminum oxide Al3+ O2- Al2O3

When writing formulas containing polyatomic ions, use parentheses around multiple polyatomic ions. ammonium carbonate NH4+ CO32- 2 1 (NH4)2CO3

strontium hydroxide Sr2+ OH- 1 2 Sr(OH)2

calcium nitrate Ca2+ NO3- 1 2 Ca(NO3)2

aluminum phosphate Al3+ PO43- 3 3 AlPO4

Monday Bellwork Practice this ion quiz: NO3- _______________________ Mercury (II) _______________________ Ag+ _______________________ CN- _______________________ Potassium _______________________ Bromide _______________________ Ba2+ _______________________

When naming ionic compounds containing a transition metal, don’t forget to include the Roman numeral for the charge. Ex. FeCl2 iron(II) chloride FeCl3 iron(III) chloride

Distinguish Between the two types of compounds! Molecular Ionic Two or more nonmetals Low melting point Low boiling point Example CO2 Metal and nonmetals High melting point High boiling point Solid at room temperature Electrically neutral Example NaCl

Which of the following is molecular and which is ionic? NaBr CO2 O3 NO KCl AlBr3 Ionic Molecular Molecular Molecular Ionic Ionic

Molecular formula- chemical formula written for a molecule Chemical formula- shows the number and kinds of atoms in the smallest representative unit of the substance. Molecular formula- chemical formula written for a molecule Ex. CO2 O2 or H2O2 The formula for this compound would be C5H12O

Formula unit- chemical formula written for an ionic compound Formula unit- chemical formula written for an ionic compound. -lowest whole-number ratio of ions in the compound

Tuesday Bellwork Name the following compounds. NaBr _____________________________ Al(OH)3 ___________________________ NH4F _____________________________ Li2SO3 ____________________________ CaBr2 ____________________________ KMnO4 ___________________________ Fe(NO3)2__________________________ LiOH _____________________________

Law of Definite Proportions- In all samples of any chemical compound, the elements are always combined in the same proportion by mass. Ex. Water is always 88.9%O and 11.1%H by mass

Law of Multiple Proportions- Whenever two elements form more than one compound, the different masses of one element that combine with the same mass of the other element are in the ratio of small whole numbers.

Formula Naming: A Summary

Wednesday Bellwork Using the food label shown, write two compounds in this food.

Thursday Bellwork Write the formulas for these compounds. Potassium chlorite Calcium hydrogen carbonate Dichlorine heptoxide Trisilicon tetranitride Sodium dihydrogen phosphate Phosphorus pentabromide Carbon tetrachloride

Friday Bellwork Study for your all ion quiz!