The Chemistry of Life Elements, Atoms, and Properties

What does Chemistry have to do with Biology? Living things are made up of simple elements as well as complex carbon compounds. If we begin to understand how these elements interact we can better understand how the body works.

Property of Matter What is matter? – Matter: anything that takes up space. Three States/Phases of matter: – Gas – Liquid – Solid

Types of Properties Physical Properties: – Anything that has a mass, volume, and weight Chemical Properties: – Describes a substances ability to change into another substance as a result of a chemical change.

Physical Properties Solids have three main properties: – It has a definite weight. Measure of force of gravity on an object – It has a definite mass. Quantity of matter in an object – It has a definite volume. Amount of space an object takes up

Physical Properties Other physical properties – Color, shape, odor, texture, taste, and hardiness – Melting point, Boiling point. Physical Properties can be: – Observed and Measured WITHOUT permanently changing the identity of matter.

Physical properties are the things we know about objects using our senses. sight taste hearing touch smell

Properties of Solid objects flexible rigid smooth rough soft hard colored pointed flat transparent opaque Bear ribbon ball book bottles pineapple Did you have other answers? Can you support your choice?

Chemical properties Ability of a substance to change into another new substance as a result of a chemical change. Chemical Change: – Process by which a substance is permanently altered. – Often difficult if not IMPOSSIBLE to reverse effects.

Phases of Matter Phases: states that an object may undergo – Solid, Liquid, and Gas. (Physical Properties)

Composition of Matter Atoms: from greek word atomos – Meaning “uncut” Building Block of ALL Matter!!!

Atomic Structure Nucleus: center most dense part of the atom. – Holds protons and neutrons. What are protons, neutrons, and electrons?

Protons and Neutrons in Nucleus Protons (Positive charged particle) Neutrons (Neutral charge)

Electrons Negative charged molecules

Energy Levels Where the electrons are.

Atomic Mass and Mass number Atomic number: – number of protons in the nucleus of an atom. Mass number: – total number of protons and neutrons.

Chemical Elements Substances, known as elements, consist entirely of one element Element: – one of over 109 different substances found in nature or created by man.

Atoms Atoms contain equal numbers of electrons and protons – Gives no charge= happy – Example Hydrogen = 1 proton and 1 electron If a atom has a charge that means that it has more electrons if negative or more protons if it is positive.

Calculating # of protons, electrons and neutrons. For any element: – Number of Protons = Atomic Number – Number of Electrons = Number of Protons = Atomic Number – Number of Neutrons = Mass Number - Atomic Number For krypton: – Number of Protons = Atomic Number = 36 – Number of Electrons = Number of Protons = Atomic Number = 36 – Number of Neutrons = Mass Number - Atomic Number = = 48

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Isotopes Atoms of the same Element with the same number of protons but different number of neutrons. For Example: Carbon – Normal = 6 neutrons – Can have 7 or 8 neutrons This is useful for scientists because some can be more reactive or unstable – This means they are very easy to break bonds causing radiation Said to be radioactive

Compounds and Bonding Chemical Compounds: – Combination of 2 or more different atoms with different properties. – When elements combine to form substances, Consisting of 2 or more different atoms, chemical compounds are produced. Example: Water H20

Interactions of Matter Chemical Bonding: – Combining of elements involving interactions – In order to achieve stability, an atom will either gain, lose, or share electrons.

Bonds Ionic Bonds Covalent Bonds

Ionic Bond Ion: charged particle Ionic Bond: involves transfer of electrons

Covalent Bonds Chemical bond formed by sharing of electrons. Molecule: combination of atoms that are held together by covalent bonds – Have no overall charge – Example: sugars, fats, proteins, water

Chemical Reactions Chemical Reactions: – Process by which a chemical change occurs – Chemists have learned that most important factors in determining whether a reaction will occur is the flow of energy.

Mixtures and Solutions Mixture: – A combination of substances in which the individual components retain their own properties. Solution: – A mixture in which one or more substances (solutes) are distributed evenly in another substance.(solvent)

Acid and Bases Depends on pH. What is pH? – A measure of how acidic or basic something is? Scale ranges Acid: – Any substance with a pH below 7. Base: – Any substance with a pH above 7

Acid Forms Hydrogen Ions: H+ in WATER. When compound HCl, hydrogen chloride is added to water. – The H+ and the Cl- form HCl – H+ and Cl- form Hydrochloride in water.

Base Forms hydroxide (OH-) ions in water. Sodium hydroxide (NaOH) is dissolved in water, it forms sodium ions (Na+) and hydroxide (OH-). The Solution has an abundance of OH- ions which creates a pH above 7.