GenChem3

• What are the three states of matter?

  Solids, liquids, and gases
• How do gases behave in terms of shape and volume?

  Gases have no definite shape and volume
• What is a characteristic of gases compared to solids and liquids?

  Gases are highly compressible
• How can matter be grouped?

  Into solids, liquids, or gases
• What are properties in relation to materials?

  Characteristics that make materials unique
• What are physical properties of matter?

  Observable characteristics without changing composition
• What are chemical properties of matter?

  Characteristics observed during chemical reactions
• How can materials be classified based on biodegradability?

  As biodegradable or nonbiodegradable
• What is the composition of all matter?

  Composed of tiny particles called atoms
• What distinguishes pure substances from mixtures?

  Pure substances have a fixed composition
• What is a pure substance?

  A matter with a definite or fixed composition
• What are the two classifications of pure substances?

  Elements and compounds
• What is an element?

  Made up of one kind of atom
• What is a compound?

  Made up of different kinds of atoms
• How do compounds differ from the elements that make them up?

  Compounds have different properties from their elements
• What cannot decompose an element?

  Physical or chemical means
• What happens to the identity of pure substances during physical changes?

  It does not change
• Why is gold suitable for jewelry making?

  It is malleable and has a low melting point
• How many elements are known to exist?

  118 elements
• What is the periodic table of elements?

  An arrangement of all known elements
• What distinguishes metals from nonmetals in the periodic table?

  Metals are solid at room temperature
• What are the properties of metals?

  Shiny, malleable, ductile, and good conductors
• What is unique about mercury among metals?

  It is liquid at room temperature
• What are some uses of magnetic metals?

  In electric motors and storage devices
• What are the characteristics of nonmetals?

  Gaseous or dull solids, brittle, poor conductors
• What are metalloids?

  Elements with properties of both metals and nonmetals
• What is the only nonmetal that is liquid at room temperature?

  Bromine
• Why are metalloids known as semiconductors?

  They conduct heat and electricity moderately
• What are compounds composed of?

  Two or more different elements combined
• How are compounds formed?

  Through chemical reactions between elements
• What is the fixed mass ratio in compounds?

  Elements exist in a specific mass ratio
• How many atoms are in a water molecule?

  Three atoms: two hydrogen and one oxygen
• What holds the atoms in a compound together?

  Strong attractive forces
• What is the significance of the fixed composition of pure substances?

  It ensures consistent properties regardless of amount
• What happens when elements react with one another?

  A new substance in the form of a compound is formed
• What is the chemical symbol for Oxygen?

  O
• What is the chemical symbol for Calcium?

  Ca
• What is the first letter of a chemical symbol?

  Always capitalized
• What is the second letter of a chemical symbol?

  Always lowercase
• What is the arrangement of elements in the periodic table based on?

  Their chemical properties