Unit One: Exam Study Guide Elements and Compounds Vocabulary Matter Atom Molecule Elements Properties Substance Compound Mixture Chemical Formula Subscripts Chemical Symbol Composition States of Matter Physical Change Chemical Change Precipitate Elements ****Be sure you know all of the Elements and Chemical Symbols we have covered so far. Hydrogen -H Oxygen - O Sodium - Na Carbon - C Chlorine - Cl Nitrogen - N Sulfur - S Silicon - Si Elements and Compounds ➢ Matter is anything that has mass and takes up space. ➢ Atoms make up elements and are the smallest most basic part of an element. Each element consists of its own kind of atom, with its own unique properties. ➢ Properties of an element: An element is a pure substance and cannot be broken down into simpler substances by a physical or chemical change. ➢ Elements are pure substances and every element known to man is listed on the Periodic Table of Elements. ➢ The Periodic Table of Elements lists all known pure substances that exist in the world. ➢ Each element is represented by its own C hemical Symbol. ○ (H = Hydrogen) ➢ A Compound is two or more elements chemically bonding together to form a new substance, a compound can be represented with a chemical formula (H2O) ➢ A Mixture is a physical combination of 2 or more substances. Each substance maintains its own identity. ➢ Know the arrangement of atoms that represent an element. ➢ Know the arrangement of atoms that represent a compound. ➢ Know the arrangement of atoms that represent a Mixture. ➢ Know how to tell the difference between an element and a c ompound by identifying their Chemical Symbols. ○ An element is represented by a single capital letter or a capital letter followed by a lowercase letter (Na) or (H) ○ A compound is represented by two or more chemical symbols placed together. (CO2) or (H2O) ○ Count the number of capital letters to determine the number of elements present. ➢ Properties are characteristics or traits used to describe matter by observation. (The banana is long, yellow and solid) States of Matter ➢ 3 states of matter: Solid, Liquid and Gas. ➢ Know that with heating or cooling, the state of matter can be changed. ○ As the temperature increases a solid can change to liquid ○ As the temperature is increases a liquid can change to a gas (evaporation) ○ As the temperature decreases a gas can change to a liquid ○ As the temperature decreases a liquid can change to a solid Physical Change and Chemical Change ➢ When a Physical Change takes place, chemical makeup stays the same. Look at the evidence involving a Physical Change ○ Size ○ Shape ○ State of Matter (solid, liquid, gas) ➢ When a Chemical Change takes place a new chemical substance is formed. Look at the evidence involving a Chemical Change ○ Gas is produced ○ Temperature change ○ A precipitate is formed ○ Color change ➢ A precipitate is a solid that is formed during a chemical reaction between two liquids.