11Chem

• What is matter made up of?

  Various particles
• What are the two main types of matter?

  Elements and compounds
• How is an element defined?

  It is made up of one type of atom
• What distinguishes a compound from its constituent elements?

  A compound has properties different from those of the elements that make it up
• What is a mixture?

  Two or more substances physically combined together
• What is a pure substance?

  A substance with a definite and constant composition made up of one type of particle
• What is the difference between homogeneous and heterogeneous mixtures?

  Homogeneous mixtures are uniform in composition, while heterogeneous mixtures are non-uniform
• What is a characteristic of solids?

  They have a definite volume and shape
• What are the three states of matter?

  Solid, liquid, and gas
• How do liquids differ from solids in terms of shape?

  Liquids have a definite volume but changeable shape
• What is a characteristic of gases?

  They have no definite volume and can expand to fill their container
• What happens to particle movement when temperature increases?

  Particle movement increases
• What is a solution?

  A homogeneous mixture where dispersed particles cannot be seen with a microscope
• What is the role of a solvent in a solution?

  It is the liquid that usually does the dissolving
• What is a solute?

  The particles that are getting dissolved in the solvent
• What is a suspension?

  A heterogeneous mixture where dispersed particles can be seen and settle out over time
• What is a physical change?

  A change where no new substances are formed and is usually easy to reverse
• What indicates a chemical change?

  Formation of a new substance, color change, temperature change, or production of a smell
• What are reactants in a chemical reaction?

  The starting substances
• What are products in a chemical reaction?

  The substances that are formed
• Why do chemical changes often require more energy than physical changes?

  Because they involve the formation of new substances
• What is the Particle Theory?

  A theory that explains the behavior of particles in solids, liquids, and gases
• How do particles behave in solids?

  They are dense, packed, and vibrating
• How do particles behave in liquids?

  They can move more freely than in solids
• How do particles behave in gases?

  They move faster and are further apart
• What is an atom?

  The smallest particle that makes up matter
• What is a molecule?

  Two or more atoms bonded tightly together
• What are ions?

  Positively or negatively charged atoms
• What is the purpose of separating mixtures?

  It helps in filtering and research
• What is sedimentation?

  A method of separating substances based on their density
• What is filtration?

  A method to separate solids from fluids
• What is evaporation in the context of separating mixtures?

  A method to separate fluids by increasing concentration
• What is the structure of an atom?

  It consists of a positively charged nucleus with electrons orbiting around it
• What are the three subatomic particles in an atom?

  Protons, neutrons, and electrons
• How does the size of an electron compare to protons and neutrons?

  Electrons are 1800 times smaller than protons and neutrons
• What is the charge of a proton?

  +1
• What is the charge of a neutron?

  0
• What determines the identity of an element?

  The number of protons in its atoms
• What is the atomic number?

  The number of protons in an atom
• What is the mass number?

  The number of protons plus neutrons in an atom