Matter

Standard 5 Understand the structure of an atom in terms of its subatomic particles; isotopes and ions; differentiate between the classification and separation of matter (mixtures, pure substances…)

Matter Matter: Anything that has mass and takes up space.

 Building blocks of matter.  Contains subatomic particles:  Electrons  Neutrons  Protons Atoms

Subatomic Particles  Protons and electrons are the only particles that have a charge.  Protons and neutrons have essentially the same mass.  The mass of an electron is so small we ignore it.

Symbols of Elements Elements are symbolized by one or two letters. C 12 6 Mass number (number of protons plus neutrons) Atomic number (number of protons) Resulting Charge Symbol of the Element

Atomic Number C 12 6 Mass number (number of protons plus neutrons) Atomic number (number of protons) Resulting Charge Symbol of the Element All atoms of the same element have the same number of protons

Atomic Mass C 12 6 Mass number (number of protons plus neutrons) Atomic number (number of protons) Resulting Charge Symbol of the Element The mass of an atom in atomic mass units (amu) is the total number of protons and neutrons in the atom.

Determining Electrons C 12 6 Mass number (number of protons plus neutrons) Atomic number (number of protons) Resulting Charge Symbol of the Element In elements the # of protons = the # of electrons, so the element is electrically neutral and no charge is shown. However atoms can gain or lose electrons to become ions and the resulting charge is shown.

Isotopes Atoms of the same element with different masses. Isotopes have different numbers of neutrons C 12 6 C 13 6 C 14 6 C

Practice Symbol# of Protons # of Neutrons # of Electrons Net Charge n I As 75 33

States of Matter Deposition Sublimation

Classification of Matter

Properties and Changes of Matter

Properties of Matter Physical Properties: □Can be observed without changing a substance into another substance. Boiling point, density, mass, volume, etc. Chemical Properties: □Can only be observed when a substance is changed into another substance. Flammability, corrosiveness, reactivity with acid, etc.

Changes of Matter Physical Changes: □Changes in matter that do not change the composition of a substance. Changes of state, temperature, volume, etc. Chemical Changes: □Changes that result in new substances. Combustion, oxidation, decomposition, etc.

Chemical Reactions In the course of a chemical reaction, the reacting substances are converted to new substances.

Chemical Separation of Matter Electrolysis Compounds can be broken down into more elemental particles.

Physical Separation of Mixtures

Daily Activity 10/7/2011 Symbol# of Protons # of Neutrons # of Electrons Net Charge Bh Zn 35 30

Distillation: Separates homogeneous mixture on the basis of differences in boiling point.

Filtration: Separates solid substances from liquids and solutions.

Chromatography: Separates substances on the basis of differences in solubility in a solvent.

Chemisty

 Sum of the atomic weights for the atoms in a chemical formula  So, the formula weight of calcium chloride, CaCl 2, would be Ca: 1(40.1 amu) + Cl: 2(35.5 amu) amu  These are generally reported for ionic compounds

 Sum of the atomic weights of the atoms in a molecule  For the molecule ethane, C 2 H 6, the molecular weight would be C: 2(12.0 amu) + H: 6(1.0 amu) 30.0 amu

One can find the percentage of the mass of a compound that comes from each of the elements in the compound by using this equation: % element = (number of atoms)(atomic weight) (FW of the compound) x 100

So the percentage of carbon in ethane is… %C = (2)(12.0 amu) (30.0 amu) 24.0 amu 30.0 amu = x 100 = 80.0%

What are the masses of each of the following in grams? a. Carbon b. Oxygen Opening Problem c. Hydrogen d. Water e. CH 4 f. H 2 CO 3

 Carbon: 12.01g  Oxygen: 16.00g  Hydrogen: 1.01g  Water: H 2 O:  CH 4 :  H 2 CO 3 : Opening Problem 2(H) + 1(O)= =2(1.01g) + 1(16.00g) =18.02g 1(C) + 4(H)=1(12.01g) + 4(1.01g) = =16.05g 2(H) + 1(C) + 3(O)= =62.03g =2(1.01g) + 1(12.01) + 3(16.00g) =

Why don’t we deal with individual items? Would you want to purchase eggs individually? Or sheets of paper individually? Or…? Quantities are more convenient especially when individual items are small.

Mole: contains as many molecules as the number of atoms in exactly 12 g of carbon-12. Avogadro’s Number (N a ): 6.02 x molecules/mole Molar Mass: Mass of one mole of substance, the same as formula mass.

The Mole is a quantity defined by Avogadro’s Number as 6.02 x of something 602,000,000,000,000,000,0 00,000 How big is this number??

 If you were able to count at the rate of 1 million numbers a second, it would take about 20 billion years to count out one mole.

 If you had Avogadro's number of unpopped popcorn kernels, and spread them across the United States of America, the country would be covered in popcorn to a depth of over 9 miles.

What if you had a mole of pennies and you gave each individual in the world an equal share… If each person spent one million dollars per day it would take 2,750 years for a person to squander away his or her fortune. However life would be quite uncomfortable though since we would be buried to a depth of 75meters in copper coins.

 Enough soft drink cans to cover the surface of the earth to a depth of over 200 miles.

How big is a mole of water????

 6.02 x  1 mole of 12 C has a mass of 12 g

11 dozen cookies = 12 cookies 11 mole of cookies = 6.02 X cookies 11 dozen cars = 12 cars 11 mole of cars = 6.02 X cars 11 dozen Al atoms = 12 Al atoms 11 mole of Al atoms = 6.02 X atoms Note that the NUMBER is always the same, but the MASS is very different! Mole is abbreviated mol (gee, that’s a lot quicker to write, huh?)

 By definition, these are the mass of 1 mol of a substance (i.e., g/mol) ◦ The molar mass of an element is the mass number for the element that we find on the periodic table ◦ The formula weight (in amu’s) will be the same number as the molar mass (in g/mol)

Moles provide a bridge from the molecular scale to the real-world scale

 One mole of atoms, ions, or molecules contains Avogadro’s number of those particles  One mole of molecules or formula units contains Avogadro’s number times the number of atoms or ions of each element in the compound

Molar mass can be used as a conversion factor. Ex/ g  mol, 12.01g C =1mol, or 18.02g H 2 O = 1mol.

Avogadro’s number can also be used a conversion factor: 6.02x10 23 molecules = 1mol Ex/ molecules  mol, mol  atom

Dimensional analysis can be used to convert from g  atom and molecule  g

 Formula Mass of: ◦ CH 3 OH ◦ K 2 SO 4  Convert from g  mol, mol  g ◦ 7.05g Cl 2 ◦ 1.31mol C 4 H 10  Convert from g  molecule, atom  g ◦ 201g PbCrO 4 ◦ 1.63x10 23 atoms S