Biochemistry Biophysics SCIENCE BIOLOGICAL (Living) Biology Anatomy Zoology Genetics PHYSICAL (Non-living) Chemistry Physics Astronomy Geology Biochemistry Biophysics

What is Chemistry? Chemistry is the study of the composition, structure and properties of matter, the processes that matter undergoes, and the energy changes that accompany these processes. Chemistry is the study of atoms and how they interact

Branches of Chemistry Organic Chemistry – study of carbon-containing compounds Inorganic Chemistry – study of non-organic substances Physical Chemistry – study of properties and changes of matter and their relation to energy Analytical Chemistry – the identification of components and composition of materials Biochemistry – the study of substances and processes occurring in living things Theoretical Chemistry – the use of mathematics and computers to understand principles behind observed chemical behavior and to design and predict properties of new compounds

Types of Research Basic Research – knowledge for knowledge’s sake Applied Research - done to reach particular goals defined by specific need to solve a problem Technological Development – produce products that improve our quality of life

What is Matter? Matter is anything that has mass and takes up space Mass is a measure of matter

Properties of Matter Atom - smallest unit of an element that maintains the chemical identity of that element Element – a pure substance that can not be broken down into simpler, stable substances; made of one type of atom Compound - a substance made up of 2 or more types of atoms chemically bonded that can be broken down into simpler substances by chemical means; each substance loses its own properties, and gains new properties

Classifying Matter Matter falls into 2 categories: Pure Substances or Mixtures Pure Substance – has same type of particle throughout - element or compound only Mixture –two or more substances that have a variable composition, physically combined - not chemically joined - each substance retains own properties

Mixtures Homogeneous Mixture – same throughout, or uniform in composition. Also known as a solution Heterogeneous Mixture – not uniform throughout, contains regions with different properties

Matter Can it be separated? Pure substances Mixtures YES NO Pure substances Mixtures Can it be decomposed by ordinary chemical means? Is the composition uniform? Homogeneous mixtures (air, sugar in water, stainless steel) Heterogeneous mixtures (granite, wood, blood) Compounds (water, sodium chloride, sucrose) Elements (gold, aluminum, oxygen, chlorine)

Physical Properties of Matter Intensive Property – does not depend of amount of matter present Extensive Property – depends on the amount of matter present

Physical Properties and Changes Physical Property – a characteristic that can be observed or measured without changing the identity of the substance Physical Property – a change that doesn’t involve change in identity

Chemical Properties and Changes Chemical Property – describe a substance’s ability to be transformed into a different substance Chemical Change – a change that does involve a change in identity or a chemical reaction

Clue words that identify a Physical or Chemical change Grinding Reacts Cutting Decomposes Melting Combines Boiling Decays Mix Oxidizes Stir Synthesized Bend Produce a gas/fizzes Dissolve Burns Vaporize Tarnishes Condense Corrodes Shake Reduces Agitate Combusts

Physical States of Matter Solid - defined volume and shape Tigthly packed particles Low kinetic energy Liquid – a definite volume but indefinite shape Tightly packed particles, with loose attraction to one another Gas – neither definite volume or shape Particles are far apart, can be compressed High kinetic energy Plasma – high temperature state in which atoms lose most of their electrons Ex. – fluorescent bulbs, lightning, and the sun

Energy and Changes in Matter Energy is always involved in physical or chemical changes Energy comes in two forms: Kinetic energy – energy of motion Potential Energy – stored energy Chemical energy is stored in chemical bonds that hold atoms together Can be released as heat or light

Energy in Chemical Reactions Exothermic – Reactions that release energy Endothermic – Reactions that absorb energy