chemistry

• What is an element?

  A substance that cannot be broken down
• What is an atom?

  Smallest particle of an element
• What is the nucleus of an atom?

  Center of an atom
• What are the two subatomic particles in atomic nuclei?

  Protons and neutrons
• What charge do protons have?

  Positively charged
• What determines the identity of an element?

  The number of protons in the nucleus
• What is the atomic number?

  Number of protons in the nucleus
• What charge do neutrons have?

  Neutral charge
• What do neutrons add to the nucleus?

  Mass to the nucleus
• How is atomic mass calculated?

  Protons + neutrons in the nucleus
• What are electrons?

  Negatively charged particles orbiting the nucleus
• Where do electrons orbit in an atom?

  In an electron cloud outside the nucleus
• What is the relationship between protons and electrons in an atom?

  Number of protons equals number of electrons
• What is the electron cloud divided into?

  Energy levels and sublevels
• How many electrons can the 1st energy level hold?

  Up to 2 electrons
• How many electrons can the 2nd energy level hold?

  Up to 8 electrons
• How many electrons can the 3rd energy level hold?

  Up to 18 electrons
• How many electrons can the 4th energy level hold?

  Up to 32 electrons
• What are isotopes?

  Atoms of the same element with different neutrons
• Give an example of an isotope of carbon.

  Carbon-12 and Carbon-14
• What is a compound?

  Substance composed of two or more elements
• How do the properties of a compound compare to its elements?

  Different than the properties of its elements
• What do chemical bonds do?

  Hold compounds together
• What are the two main types of chemical bonds?

  Covalent and ionic bonds
• How do covalent bonds form?

  Atoms share electrons to form a compound
• What are ions?

  Atoms that have gained or lost electrons
• What are anions?

  Atoms that gain electrons and have a negative charge
• What are cations?

  Atoms that lose electrons and have a positive charge
• Do ionic bonds form molecules?

  No, ionic bonds do not form molecules
• What must chemical equations obey?

  The Law of Conservation of Matter
• What is a balanced equation?

  Number of atoms before equals after reaction
• What are the two parts of every chemical reaction?

  Reactants and products
• What is a mixture?

  Combination of substances retaining their properties
• What are the two types of mixtures?

  Homogeneous and heterogeneous mixtures
• What is a solution?

  Mixture where one substance is dissolved in another
• What is the universal solvent?

  Water
• What is the pH range of acids?

  0 to 6
• What is the pH range of bases?

  8 to 14
• What pH is considered neutral?

  7
• What does the pH scale measure?

  Concentration of hydrogen ions in solution