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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.

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Basic Chemistry Concepts

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  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)

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