1 / 18

Basic Chemistry Concepts

Basic Chemistry Concepts. Structure and function of all living things are governed by the laws of Chemistry Understanding of Chemistry’s fundamental principles provides a better understanding of living things and how they function. Composition of Matter.

Télécharger la présentation

Basic Chemistry Concepts

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. Basic ChemistryConcepts Structure and function of all living things are governed by the laws of Chemistry Understanding of Chemistry’s fundamental principles provides a better understanding of living things and how they function

  2. Composition of Matter • Everything in the universe is made of matter • Matter is anything that has mass and takes up space

  3. Elements • Pure substances that cannot be broken down chemically into simpler kinds of matter • Periodic Table gives: • Atomic Number • Chemical Symbol • Atomic Mass

  4. Of more than 100 elements, fewer than 30 are important in living things • More than 90% of the mass of living things is composed of: • Oxygen (O) • Carbon (C) • Hydrogen (H) • Nitrogen (N)

  5. Atoms • Simplest particle of an element that retains all of the properties of that element • Basic building blocks of all matter • Contain 3 types of particles: • Protons • Neutrons • Electrons

  6. The Nucleus of an Atom • The central core of an atom • Most of the mass is here • Contains two kinds of particles • Protons: POSITIVE CHARGED PARTICLE • All atoms of an element have the same number of protons • Number of protons = atomic number • Neutrons: NO ELECTRICAL CHARGE • Number of protons + neutrons = atomic mass • Same element with different neutrons: isotopes

  7. Electrons • Third type of atomic particle • NEGATIVELY CHARGED PARTICLES • Very small and move around the nucleus at very high speeds • Number electrons = number protons

  8. Electrons move in different energy levels • Each energy level can hold only certain # of electrons • 1st level: 2 • 2nd and other outer levels: 8 • A stable atom is one that has a full outer level

  9. Compounds • Pure substances that are made up of atoms of two or more elements that are chemically combined • Proportion of each kind of atom is fixed (for example, H2O: chemical formula)

  10. Compound properties (physical and chemical) are different from individual element properties • Elements tend to combine depending on number and arrangements of electrons • Working toward more stable state NaCl

  11. Chemical Reactions and Bonds • Atoms undergo chemical reactions to become more stable • In reactions, chemical bonds are broken, atoms rearranged, and new bonds (or attachments) are formed • Metabolism: all of the chemical reactions that occur in an organism • Two types of chemical bonds: • Covalent Bonds • Ionic Bonds

  12. Covalent Bonds • Two atoms SHARE one or more pairs of electrons • Most compounds in organisms have covalent bonds • A group of atoms held together by covalent bonds is called a molecule

  13. Ionic Bonds • Formed by electrical attraction between two oppositely charged ions • Ion: atom or molecule with an electrical charge

  14. Energy and Chemical Reactions • Energy is required to make or break chemical bonds, at least for the reaction to begin • Chemical reactions that involve a net release of energy: exergonic reactions • May be used to do other work • Chemical reactions that involve a net absorption of energy: endergonic reactions

  15. Catalysts in Chemical Reactions • For many compounds, the amount of energy needed to start the reaction (called activation energy) is HIGH • Catalysts are chemical substances that reduce the amount of activation energy needed • With a catalyst, the reaction may proceed spontaneously or with only small amount of energy • Enzymes are important catalysts in living things

  16. Chemical Equations • Shows the changes occurring in a chemical reaction • Reactants are on the LEFT side • Products are on the RIGHT side

  17. Solutions • Mixtures in which one or more substances are UNIFORMLY distributed in another substance (example: sugar water) • Sugar is the solute (substance dissolved) • Water is the solvent (substance in which the solute is dissolved) • Aqueous solution: water is the solvent • Universally important in living things

  18. Acids and Bases • On ph Scale from 0-14 • 0 = very acidic (more H+ ions) • 7 = neutral • 14 = very basic or alkaline (more OH- ions) • Buffers neutralize solutions (example of homeostasis in living things)

More Related