Chapter 2 What is Matter?

Chemistry Considered a central science because it touches all the other sciences

Submicroscopic World ATOMS –Small –Single grain of sand contains 125 million trillion atoms MOLECULES –Linked atoms –8oz glass of water contains a trillion trillion H 2 O molecules

Nitrogen a)Atom b)Molecule

Au is gold on the periodic table a)Atom b)Molecule

H2OH2O a)Atom b)Molecule

H 2 O as ice a)Atom b)Molecule

H 2 O as vapor a)Atom b)Molecule

H2OH2O a)Atom b)Molecule whether solid liquid or gas

O2O2 a)Atom b)Molecule

He (Helium) a)Atom b)Molecule

CO 2 a)Atom b)Molecule

N2N2 a)Atom b)Molecule

N2N2 a)Atom b)called a Diatomic Molecule

ELEMENT –Made of only one type of atom Distinction – elements are made of atoms, and not the other way around COMPOUNDS –Made of 2 or more elements –Every compound’s properties are different than the elements it contains

H2SH2S a)Element b)Compound

Ne a)element b)compound

Po a)element b)compound

H2O2H2O2 a)Element b)Compound

Chemical formulas GlucoseC 6 H 12 O 6 Hydrogen peroxide 2 H 2 O 2 MethaneCH 4 Quartz3 SiO 2 Shows the ratio of atoms used to make a compound

Number of elements in SiO 2 a)0 b)1 c)2 d)3

Total Number of atoms in SiO 2 a)0 b)1 c)2 d)3

Number of elements in 2 CaF 2 Answer = 2 : Ca is one and F is the other Answer = coefficient 2 x one Ca atom  2 + coefficient 2 x 2 atoms of F in F atoms Total Number of atoms in 2 CaF 2 two molecules of calcium fluoride

Number of elements in 2 CuCl 2 a)0 b)1 c)2 d)3 e)6

Total Number of atoms in 2 CuCl 2 a)0 b)1 c)2 d)3 e)6

Number of molecules in 2 H 2 O 2 a)0 b)2 c)4 d)6 e)8

Total number of atoms in 2 H 2 O 2 a)0 b)2 c)4 d)6 e)8

Review from yesterday

2 C 3 H 8 O (isopropyl alcohol) 1.molecule 2.atom

How many types of elements in 2 C 3 H 8 O (isopropyl alcohol)

How many types of atoms in 2 C 3 H 8 O (isopropyl alcohol)

How many molecules in 2 C 3 H 8 O (isopropyl alcohol)

How many total atoms in one molecule of 2 C 3 H 8 O (isopropyl alcohol)

total number of atoms in 2 C 3 H 8 O (isopropyl alcohol)

PURE SUBSTANCE –Fixed composition –Definite properties Examples –Elements –Compounds Note –Cannot be broken into its components MIXTURE –Varying amounts –No definite properties a.Examples –Air –Stainless steel b.Note –Can be broken into its components

MIXTURES Mixtures can be physically separated – NOT chemically combined Heterogeneous –Not evenly distributed –Not uniform Homogeneous –Evenly distributed –Same throughout ________________________ Liquid Mixtures –Miscible: dissolved –Immiscible: does not mix well; layered

Muddy water 1.pure substance 2.mixture

Salt water 1.pure substance 2.mixture

Isopropyl alcohol, C 3 H 8 O 1.pure substance 2.mixture

conglomerate 1.pure substance 2.mixture

Koolaid 1.Homogeneous 2.Heterogeneous

Air 1.Homogeneous 2.Heterogeneous

A pail of sand and water 1.Homogeneous 2.Heterogeneous

Chocolate syrup 1.Homogeneous 2.Heterogeneous

Properties of Matter PHYSICAL –Color –Hardness –Density –Texture –Phase –Mass –Volume –Conductivity –Magnetism Properties can change when conditions change, - BUT still the SAME substance

Properties of Matter CHEMICAL –Relates to how a substance reacts Combines Breaks apart – Flammability –Copper reacts with CO 2 to form patina

Changes of Matter PHYSICAL CHANGE –Affects one or more physical properties – but not the identity of atoms –Phase change Ex. Melting ice Quartz crushed into sand Dissolving

Changes of Matter CHEMICAL CHANGE –Rearrangement of atomic bonds –Chemical reaction occurs –New substance formed

Some compounds can be broken down into elements through a chemical change. Detection of change: In odor In color Fizz Heat Sound

Bending glass Demo 1.Physical change 2.Chemical change

Burning methane with the bunsen burner 1.Physical change 2.Chemical change

Distilling wood 1.Physical change 2.Chemical change

Distilling liquids left after distilling the wood 1.Physical change 2.Chemical change

Melting ice 1.Physical change 2.Chemical change

Freezing water 1.Physical change 2.Chemical change

Melting moth nuggets or flakes 1.Physical change 2.Chemical change

Freezing moth nuggest and flakes 1.Physical change 2.Chemical change

Cooking an egg 1.Physical change 2.Chemical change

Painting wood 1.Physical change 2.Chemical change