Description Conservation Laws Periodic Table...
Transcript of Description Conservation Laws Periodic Table...
Previous Material
• Accuracy & precision
• Significant Figures
• SI Units LengthMassTemperatureMole
• Conversionswithin MetricEnglish-Metric
• Medical Dose Units
Simple Definitions
• Matter – anything which has mass and occupies space
• Energy – the ability to do work
Copper atoms on silica surface.
• An atom is the smallest particle of an element that has the chemical properties of the element.
Distance across = 1.8 nanometer (1.8 x 10-9 m)
Conservation
• Conservation of Matter - matter is neither created nor destroyed
must account for all matter during a reaction
• Conservation of Energy - energy is neither created nor destroyed, changed from one form to another
must account for all energy
Three States of Matter
• Solid – defined shape and volume• Liquid – adopt shape of container
and defined volume• Gas – adopt shape and volume of
container
(pages 55 – 57, table 2.7, textbook)
Matter ClassificationDescription of Matter
Heterogenous(mixtures)
Elements Compounds
Pure Substances Solutions
Homogenous
Matter
ElementElement
Pure substance that cannot be Pure substance that cannot be decomposed any further by ordinary decomposed any further by ordinary meansmeansAbout 115 elements listed on Periodic About 115 elements listed on Periodic TableTable
metals, nonmetals, non--metals, metalloids,metals, metalloids,atomic number, atomic symbolatomic number, atomic symbol
Periodic TablePeriodic TableDmitri Mendeleev developed the Dmitri Mendeleev developed the modern periodic table. Argued that modern periodic table. Argued that element properties are element properties are periodic periodic functions of their atomic weightsfunctions of their atomic weights..We now know that element We now know that element properties are periodic functions of properties are periodic functions of their their ATOMIC NUMBERSATOMIC NUMBERS..
Group 1A: Alkali MetalsLi, Na, K, Rb, Cs
Group 1A: Alkali MetalsGroup 1A: Alkali MetalsLi, Na, K, Li, Na, K, RbRb, Cs, Cs
Cutting sodium metalCutting sodium metal
MagnesiumMagnesium
Magnesium Magnesium oxideoxide
Group 2A: Alkaline Earth MetalsGroup 2A: Alkaline Earth MetalsBe, Mg, Ca, Be, Mg, Ca, SrSr, , BaBa, Ra, Ra
Group 7A: HalogensF, Cl, Br, I, At
Group 7A: HalogensGroup 7A: HalogensF, F, ClCl, Br, I, At, Br, I, At
Group 8A: Noble Gases He, Ne, Ar, Kr, Xe, RnGroup 8A: Noble Gases Group 8A: Noble Gases He, He, NeNe, , ArAr, Kr, , Kr, XeXe, , RnRn
Group 6A: O, S, Se, Te, PoGroup 6A: O, S, Se, Te, PoGroup 6A: O, S, Se, Te, Po
Sulfuric acid dripping Sulfuric acid dripping from snotfrom snot--titetite in cave in cave
in Mexicoin MexicoElemental S has a ring Elemental S has a ring
structure.structure.
Transition ElementsTransition ElementsTransition Elements
Lanthanides and actinidesLanthanides and actinidesIron in air gives Iron in air gives iron(III) oxideiron(III) oxide
Forms of the ElementsForms of the Elements
Most are Most are monoatomicmonoatomic –– a single atom is the a single atom is the element, examples:element, examples: Zn (s), Al (s), Cs (s)Zn (s), Al (s), Cs (s)Some are Some are DiatomicDiatomic –– two atoms bound two atoms bound together form the element (not single atom together form the element (not single atom shown of Periodic Table)shown of Periodic Table)HH2 2 (g); N(g); N22 (g); O(g); O22 (g); F(g); F22 (g); Cl(g); Cl22 (g); (g); BrBr22 (l); I(l); I22 (s); (s);
Periodic TrendsPeriodic Trends
Properties of elements Properties of elements that may be predicted that may be predicted by relative position on by relative position on Periodic TablePeriodic Table
Metal CharacterMetal CharacterAtomic SizeAtomic SizeIonization EnergyIonization EnergyElectronegativityElectronegativity
See: Pages 99See: Pages 99--101,101,textbooktextbook
CompoundCompound
Pure substance composed of two or more Pure substance composed of two or more elements bonded together in a definite ratio by elements bonded together in a definite ratio by weight. weight.
Identified by a unique set of physical and Identified by a unique set of physical and chemical properties.chemical properties.
HH22O and HO and H22OO22
NaNa22CrOCrO44 and Naand Na22CrCr22OO77
CompoundsCompounds
Same three component elements Same three component elements –– Na, Cr, Na, Cr, but different weight ratiosbut different weight ratios
NaNa22CrOCrO44 NaNa22CrCr22OO77
Comparison of Physical PropertiesWater and Hydrogen Peroxide
Water Hydrogenperoxide
Melting point °C 0.0 - 2
Boiling point °C 100 158
Density, g/mL 1.0 1.46
Terms for Matter
• Heterogeneous• Homogeneous• Mixture• Solution• Physical process• Chemical process
• Element• Compound• Atom• Period• Family• Metal
Classification of Energy(pages 40 –41, textbook)
Description of Energy
Potential(position or stored)
Kinetic(motion)
Energy
ENERGYENERGY is the capacity is the capacity to do work or transfer to do work or transfer heat.heat.
HEATHEAT is the form of is the form of energy that flows energy that flows between 2 objects between 2 objects because of their because of their difference in temperature.difference in temperature.Other forms of energy Other forms of energy ——••lightlight••electricalelectrical••kinetic and potentialkinetic and potential
Potential EnergyPotential energy is stored energy and the energy of position––There are
several forms of potential energy. Chemical Energy is energy stored in the bonds of atoms and molecules. It is the energy that holds these particles together. Biomass, petroleum, natural gas, and propane are examples of stored chemical energy. Stored Mechanical Energy is energy stored in objects by the application of a force. Compressed springs and stretched rubber bands are examples of stored mechanical energy. Nuclear Energy is energy stored in the nucleus of an atom––the energy that holds the nucleus together. The energy can be released when the nuclei are combined or split apart. Nuclear power plants split the nuclei of uranium atoms in a process called fission. The sun combines the nuclei of hydrogen atoms in a process called fusion. Scientists are working on creating fusion energy on earth, so that someday there might be fusion power plants.Gravitational Energy is the energy of position or place. A rock resting at the top of a hill contains gravitational potential energy. Hydropower, such as water in a reservoir behind a dam, is an example of gravitational potential energy.
Kinetic EnergyE = 1/2 mv2
E = energy (Joules)m = mass (kilograms)v = speed (meters/sec.)
Marion Jones Sprints to Victory in the 200 meter.
Kinetic Energy
Kinetic energy is motion––of waves, electrons, atoms, molecules, substances, and objects. Electrical Energy is the movement of electrical charges. Electrical charges moving through a wire is called electricity. Radiant Energy is electromagnetic energy that travels in transverse waves. Radiant energy includes visible light, x-rays, gamma rays and radio waves. Light is one type of radiant energy. Thermal Energy, or heat, is the internal energy in substances––the vibration and movement of the atoms and molecules within substances. Geothermal energy is an example of thermal energy. Motion Energy is the movement of objects and substances from one place to another. Wind is an example of motion energy.