Periodic Table of Elements MEET THE ELEMENTS Pages 124-167 Ch.4.1, 4.2, 4.3, 4.4 and 5.1

Dmitri Mendeleev He recognized patterns in the element’s approximate atomic masses and their ability to bond with other elements.

Periodic Table Based on atomic masses and their ability to bond with other elements, Mendeleev constructed the first periodic Table.

The Atom Nucleus: The core of the atom that contains two different subatomic particles.

The Atom cont… Protons: Have a positive charge. The number of protons equals the number of electrons.

Neutrons: Have no Charge. The Atom cont… Neutrons: Have no Charge.

Electrons Negative charge. The Atom cont… Electrons Negative charge. .

Atomic Numbers, Symbols and Mass Atomic number is the smaller number and the number of protons in the nucleus. Element Symbol 47 Ag Silver 107.868 Element Name Atomic mass is the average mass of all the known isotopes.

How to calculate # of neutrons Mass number - Atomic number = # of neutrons This element is Nitrogen. Its mass # is 14. So mass # of 14, minus atomic # of 7, equals 7 neutrons. Count the number of protons. What element is it?

How to Calculate Number of Electrons The number of electrons equal the number of protons. 7 electrons 7 protons

How many neutrons does Mn (Manganese) have? 30 25 55 7 30

How many Neutrons does K (Potassium) have? 19 20 39 11 10 0 of 30

How many Protons does Hg Have? 30 80 200 120

How many Electrons does Hg Have? 30 80 200 120

Isotopes When atoms of the same element have a different number of neutrons

Valence Electrons The electrons on the outermost ring or energy level that can be shared or transferred with other atoms to make compounds.

Valence Electrons and Bonding (ch. 5.1 pgs. 176-182) The number of valence electrons in an atom of an element determines many properties of that element, including the ways in which the atom can bond with other atoms.

When an atom has a different # of neutrons it’s called a… Ion Isotope Proton Element 0 of 30

What subatomic particle influences an elements ability to bond? 30 Protons Neutrons Valence Electrons Nucleus

Groups –Families elements in a group have very similar characteristics i.e. bonding, reactivity, valence electrons Periods- elements in a period are not alike, but gradually change as you move from left to right.

Almost 75% of all elements are classified as metals.

Properties of Metals Conductors: Metals are good at conducting electricity. Malleable: Ability to bend or pound into shapes.

Properties of Metals Ductile: Pull or stretch into wire. Many are shiny, hard and magnetic. High melting point

Which of the following would be the best conductor of electricity? Carbon (atomic number 6) Strontium (atomic number 38) Tellurium (atomic number 52) of 30

What is a characteristic of metals? Gas Stable Good conductor Brittle 30

Metals are malleable, which means… Pound or mold into shape Brittle Stretch into wire of 30

What do all elements in a group/family have in common? Same # of Valence electrons Same # of protons Same # of rings/shells/energy levels of 30

ALKALI METALS-Group 1 So reactive that they are never found isolated in nature, only combined with other elements.

ALKALI METALS-Group 1 Characteristics Properties: Soft Shiny One valance: electron makes them very reactive.

The Sodium in the class demo reacted so violently because it has… 30 3 protons 1 neutron 2 valence electrons 1 valence electron

What family is Hydrogen in? Alkali Alkaline Earth Halogens No Family 0 of 30

Ca: important for bones. Alkaline Earth Metals Group 2 metals. Very reactive, not as reactive as alkali metals due to having one more valence electron. Ca: important for bones.

Metalloids Have some properties of both metals and nonmetals. They are located on the zigzag line between the metals and the nonmetals. Physical Properties: Can be good at conducting electricity, therefore some are used as computer chips such as Si and Ge.

Non-metals Non metals lack properties of metals. They are on the right side of the periodic table. Non-metals O Fe Fe2O3 = Iron Oxide = Rust Non metals usually react with metals to make compounds. In general, metals give up electrons to non-metals.

Properties of Metals cont… Reactivity: Ability to react and combine with other elements. Some are more reactive than others. Sodium (Na) and potassium (K) are some of the most reactive metals.

Which of the following elements is most likely to react? Chlorine Helium Iron of 30

What are the group 17 (7A) elements called? 30 Alkaline Earth Rare Earth Halogen Transition Metals

What is the Group/Family name of the elements in BLUE? 30 Alkali Alkaline Earth Transition Metalloids Halogen Noble Gas Rare Earth

What is the Group/Family name of the elements in RED? 30 Alkali Alkaline Earth Transition Metalloids Halogen Noble Gas Rare Earth

What is the Group/Family name of the elements in GREEN? 30 Alkali Alkaline Earth Transition Metalloids Halogen Noble Gas Rare Earth

Predicting Reactions Elements become more stable as they gain more valence electrons. As a result, atoms will gain, lose or share electrons to form compounds so that they have 8 valence electrons or a full shell. This is called the Octet Rule. However there are many exceptions, but this is an easy way to predict common reactions.

Atoms are “happy” when they have either only 2 valence electrons (He) or 8 electrons.

Families of Non-metals The Halogen family is group 17 (7A). Each element has 7 valence electrons, therefore it commonly takes one electron away from group one metals to make compounds.

Families of Non-metals The Noble Gases are group 18 (8A). They have 8 valence electrons, therefore they are very stable and non-reactive.

Not a part of group 1. Generally found as H2 Hydrogen It doesn’t fit into any other family because it is so different from all other elements.

Group 17 (7A) has 7 valence electrons and are called the 30 Alkali metals Alkaline Earth Metals Halogens Noble Gases

Group 18 (8A) has 8 valence electrons and are called 30 Alkali metals Alkaline Earth Metals Halogens Noble Gases

What element would Na (Sodium) bond with? 30 Br K W Al

What element would Mg (Magnesium) bond with? 30 Au Na Se Kr

How many Hydrogen atoms would bond to one N (Nitrogen)? 6 2 8 3

Matter Anything that has mass and takes up space

The four states of matter are solids, liquids, gasses and plasma.

Elements Can’t be broken down into another substance.

The smallest particle of an element. Basic unit of all matter Atom The smallest particle of an element. Basic unit of all matter

An ELEMENT is a pure substance made up of only one type of atom. Element vs. Compound An ELEMENT is a pure substance made up of only one type of atom. They may exist as atoms like the Noble Gases e.g. helium He or as molecules e.g. hydrogen H2 or sulfur S2

Compound EX: H20water CO2Carbon Dioxide C12022H11 Sugar Chemical Combination of 2 or more DIFFERENT elements. EX: H20water CO2Carbon Dioxide C12022H11 Sugar C6H12O6 Glucose

A type of Molecule

chocolate

Theobromine, C7H8O4N2 or Chocolate Formula Ratio of atoms of each element in a compound. Theobromine, C7H8O4N2 or Chocolate

Law of Conservation of Matter Matter is neither created nor destroyed during a chemical change. It recombines to make a new type of chemical.

Changes in Matter Physical Change: When the state of matter changes.

Physical Change whipping egg whites (air is forced into the fluid, but no new substance is produced) magnetizing a compass needle (there is realignment of groups ("domains") of iron atoms, but no real change within the iron atoms themselves). boiling water (water molecules are forced away from each other when the liquid changes to vapor, but the molecules are still H2O.) dissolving sugar in water (sugar molecules are dispersed within the water, but the individual sugar molecules are unchanged.) dicing potatoes (cutting usually separates molecules without changing them.)

Changes in Matter cont… Chemical Change: When a substance(s) combines or decompose into a new substance.

Examples of a chemical change iron rusting (iron oxide forms) gasoline burning (water vapor and carbon dioxide form) eggs cooking (fluid protein molecules uncoil and crosslink to form a network) bread rising (yeast converts carbohydrates into carbon dioxide gas) milk souring (sour-tasting lactic acid is produced) suntanning (vitamin D and melanin is produced)

Both physical and chemical change 5 Chemical change only Physical change only Both physical and chemical change

Both physical and chemical change 5 Chemical change only Physical change only Both physical and chemical change

He, O2, N2, and Ne are all: 5 Atoms Elements Compounds

5 Atoms Elements Compounds/molecules

H2, H2O, N2, and NaCl are all: 5 Atoms Elements Compounds Molecules

5 H, O, Na, Cl and C H2O, NaCl and CO2

30 Chemical change Destroying matter Physical change

A different substance with different properties 30 A change in state A different substance with different properties No new substance

Both a chemical and a physical change 30 Chemical change Physical change Both a chemical and a physical change

Characteristic Properties Regardless of state of matter, a substance has a unique characteristic property.

Chapter 3 sections 1 and 3

Definite Shape and Definite Volume.

Molecules are packed closely together and slightly vibrate.

Very large molecules made of a chain of smaller molecules Polymers form when chemical bonds link large numbers of monomers in a repeating pattern.

The properties of synthetic polymers make them ideal starting materials for many common objects.

Takes the shape of the container that it’s in.

Atoms and/or molecules are loosely packed together.

A mixture where particles can be seen and easily separated. Examples: Milk, salad dressing and muddy water

The resistance of a liquid to flow. The higher the viscosity, the slower it will flow. Usually amorphic solids.

Have no definite shape and no definite volume. Very compressible.

Particles are not touching, therefore the Intermolecular forces are broken. Movement is random and independent of each other.

What are Galaxies? They are large groups of stars There are billions of stars in a galaxy

Types of Galaxies

There are 3 main types of galaxies Spiral: it has a nucleus Irregular: it has not specific shape Elliptical: it is a bright ball and is generally older

Our Galaxy It contains over 100 billion stars It is about 100,000 light-years in diameter and 10,000 light-years thick