Chemistry of Living Things PDF

2 The Chemistry of Living Things  2.1 MATTER, ENERGY, AND LIFE  2.1 Objectives (Cues) Compare the different types of energy. Describe change in matter. Compare ionic and covalent compounds. Relate the terms matter, atom, element, proton, neutron, electron, compound, and mole...

2 The Chemistry of Living Things  2.1 MATTER, ENERGY, AND LIFE  2.1 Objectives (Cues) Compare the different types of energy. Describe change in matter. Compare ionic and covalent compounds. Relate the terms matter, atom, element, proton, neutron, electron, compound, and molecule to one another.  matter anything that takes up space and has mass  atom the building block of matter; the smallest possible particle of an element  element a pure substance made of only one kind of atom  energy the ability to do work; especially in biology, the driver of the physical and chemical processes necessary for life  temperature a measurement of the average kinetic energy of the particles within a substance  ? What would happen to living things if they didn’t have access to energy?  ? Do nonliving things also have energy?  ? What do you think the world would be like without energy?  ? What kinds of energy do you know about? Types of Energy Mechanical energy (kinetic and potential) Acoustic energy Light energy Thermal energy Electrical energy Chemical energy Forms of Energy Light Thermal Electrical Forms of Energy Thermal Chemical Forms of Energy Sound Mechanical (kinetic) Forms of Energy Mechanical (kinetic and potential) Sound Forms of Energy Light Thermal Chemical  physical change a change in a substance that does not change the identity of the substance (e.g., a change of form or state)  chemical change a change in a substance that causes it to change its chemical identity Changes in Matter Boiling water physical change Changes in Matter Baking a cake chemical change Changes in Matter Breaking a bone physical change Changes in Matter Photosynthesis chemical change Changes in Matter Is this change a physical or a chemical change? Changes in Matter Where do you think the matter goes as the candle continues to burn and gets smaller? 2C18H38(s) + 55O2(g) 36CO2(g) + 38H2O(g) Law of Conservation The amount of matter and energy in the universe never changes. Law of Conservation of Matter: Matter cannot be created or destroyed, only change forms. Law of Conservation of Energy: Energy cannot be created or destroyed, only change forms. Conserving Matter Give examples of changes in matter and energy. Point out where the “lost” energy or matter is going or where the “gained” energy or matter is coming from.  bond an electrostatic attraction that forms between atoms when they share or transfer electrons  compound a pure substance made from two or more elements that are chemically combined  Ionic Compounds When atoms in the process of bonding give away or receive valence electrons, they transform into ions. These oppositely charged ions attract to form ionic compounds. Ionic bonds typically form between a metal and a nonmetal.  formula unit anion (-) cation (+) Example of an ionic compound  Covalent Compounds Sometimes atoms in the process of bonding share their valence electrons instead of donating them. A particle consisting of two or more atoms covalently bonded together is called a molecule.  Covalent Compounds Covalent bonds usually form between two nonmetals.  hydrogen hydrogen oxygen water H2 O A molecule of water forms when two hydrogen atoms share electrons with an oxygen atom. molecule