1 / 32

Chapter 3: Matter

Chapter 3: Matter. Properties and Change. States of matter. Solid: Particles are tightly packed and do not move. Liquid: Particles are not rigidly held in place and are able to flow freely . Gas: Particles are completely free to move. Plasma: Plasma is ionized gas. .

kevyn
Download Presentation

Chapter 3: Matter

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Chapter 3: Matter Properties and Change

  2. States of matter • Solid: Particles are tightly packed and do not move. • Liquid: Particles are not rigidly held in place and are able to flow freely . • Gas: Particles are completely free to move. • Plasma: Plasma is ionized gas.

  3. Physical Properties of Matter • A physical property of matter is a characteristic that can be observed or measured without changing the sample’s composition. • Extensive Properties: Depend on the amount of the substance being studied. • Intensive Properties: Do not depend on the amount of the substance being studied.

  4. Chemical Properties of Matter • The ability of a substance to combine or change into one or more other substances is called a chemical property.

  5. Changes in Matter • Physical changes: A change that alters a substance without changing its composition. • Example: Melting ice • Chemical change: A process that changes one substance in to another substance. Also called a chemical reaction.

  6. Conservation of Mass • The law of conservation of mass states that matter cannot be created or destroyed. • In other words the mass of the reactants in a chemical reaction must be equal to the mass of the products.

  7. Mixtures of Matter • A mixture is a combination of two or more pure substances. • A heterogeneous mixture is a mixture that does not blend smoothly throughout. • A homogeneous mixture is a mixture that does blend smoothly. • Homogeneous mixtures are also referred to as solutions.

  8. Separating Mixtures • Filtration: Used to separate solids from liquids in heterogeneous mixtures • Distillation: Used to separate two liquids based on their boiling points. • Crystallization: Used to separate a pure solid from a liquid in a homogeneous mixture • Chromatography: Used to separate two liquids based on their ability to “stick” to the surface of a specific material.

  9. Elements and Compounds • An element is a pure substance that cannot be separated into simpler substances by physical or chemical means. • Example: • Anything on the periodic table • A compound is made up of two or more different elements that are chemically combined.

  10. The periodic table

  11. More about compounds • The most important thing about compounds is that the elements that make them always combine in the same proportions. • This is called The law of definite proportions. • Percent mass:

  12. Law of multiple proportions • The same two elements can combine in different proportions to create different compounds. • Example: H2O and H2O2

  13. The atom • The atom is the smallest individual unit of a given element. • All matter is composed of atoms. • Atoms are composed of three subatomic particles: • Electrons • Protons • Neutrons

  14. The electron

  15. The Nucleus • The nucleus of an atom is comprised of protons and neutrons. • Protons are subatomic particles that have a charge of +1 and a mass of 1 amu. • Neutrons are subatomic particles that do not have a charge and a mass of 1 amu. • Rutherford Experiment:

  16. How atoms differ • An atoms atomic number is the number of protons that it has. • Neutral forms of atoms have the same number of electrons as protons. • Mass number: • An atoms mass number is the sum of the atoms protons and neutrons. • Atoms with the same number of protons but different number of neutrons are called isotopes.

  17. Electrons • Before we talk more about electrons we need to talk about light. • Visible light is a type of electro magnetic radiation. • EM radiation is both a particle and a wave.

  18. Energy and atoms • Matter can only gain or lose energy in small, specific amounts called quanta. • A quantum is the minimum amount of energy that can be gained or lost by an atom.

  19. The Photoelectric effect • When atoms gain enough energy they emit electrons at certain wave lengths and energy levels (quanta). • The equation to calculate the energy of a photon emitted is: • E = hv • Where h is planks constant and v is wavelength.

  20. Atomic emission spectrum • The atomic emission spectrum of an element is the set of wavelengths of the electromagnetic waves emitted by atoms.

  21. Energy states of hydrogen • The lowest allowable energy state of an atom is called its ground state • Danish physicist Niels Bohr proposed that electrons in atoms can only have certain allowable energy states. • As electrons gain energy they are promoted to higher energy states.

  22. Quantum numbers and energy levels • Principle energy levels: • Principle energy levels are the major energy levels that electrons can occupy. • n = 1 • n = 2 • n = 3 • With in these principle levels there are sublevels • energy level one consists of one sublevel, energy level 2 consists of 2 sublevels, energy level 3 consists of 3 sublevels and so on…

  23. Quantum theory and the atom

  24. Principle energy levels • n = 1 • s • n = 2 • s • p • n = 3 • s • p • d • n = 4 • s • p • d • f

  25. Ground State electron configurations • Low energy states are more stable that high every states. • Because of this atoms like to have their electrons in their ground states. • The aufbau principle states that each electron will occupy the lowest energy level available. • The pauli exclusion principle states that the maximum number of electrons that can occupy a single atomic orbital is two. • Hund’s rule states that single electrons with the same “Spin” must occupy each equal energy orbital before additional electrons can be added.

  26. Electron configuration • Start by figuring out how many electrons and atom has. • Set up an electron configuration table. • Place electrons in orbitals one at a time before going to back to fill an orbital.

  27. Write the ground-state electron configuration for the following elements. • Boron (B) • Strontium (Sr) • Antimony (Sb) • Rhenium (Re)

More Related