intro biochem 2

    Cards (26)

    • What is the term for the region where electrons are found around an atom?
      Electron cloud
    • How are elements arranged in the periodic table?
      By increasing atomic mass
    • Who developed the periodic table in 1969?
      Mendeleev
    • What is the periodic law?
      • Elements show similar properties at regular intervals
      • Arranged by increasing atomic mass/number
    • What defines the mass of an atom?
      Atomic number and mass number
    • How do we define an isotope?
      An isotope is an atom with the same number of protons but different mass numbers
    • What is relative atomic mass (RAM)?
      It is the weighted average mass of an atom compared to 1/12th of carbon-12
    • How can we calculate RAM?
      By taking the average of the isotopes' masses weighted by their natural abundance
    • What is molecular mass?
      The sum of the atomic masses of all atoms in a molecule
    • What is the maximum number of electrons in the first shell of an atom?
      2 electrons
    • What is the valency of hydrogen?

      1
    • What happens when an atom loses an electron?
      It becomes a positively charged cation
    • What is the significance of core electrons?
      Core electrons do not form chemical bonds because they are more stable
    • What is the difference between valence electrons and core electrons?
      • Valence electrons: outermost electrons, involved in bonding
      • Core electrons: inner electrons, do not participate in bonding
    • How does atomic size change across a period?
      Atomic size decreases due to increasing nuclear charge
    • How does atomic size change down a group?
      Atomic size increases due to additional valence shells
    • What is electronegativity?
      The tendency of an atom to attract electrons in a chemical bond
    • How does electronegativity change across a period?
      Electronegativity increases across a period
    • How does electronegativity change down a group?
      Electronegativity decreases down a group
    • What is the valency of carbon?
      4
    • What is the structure of a stable methane molecule?
      • Carbon combines with 4 hydrogen atoms
      • Total of 8 electrons shared
      • Creates a stable, neutral molecule
    • What are d-orbitals?
      1. orbitals are regions where valence electrons occupy in period 4 elements
    • Which group of elements is likely to share electrons?
      Group 18 elements
    • What is the reactivity of elements in group 18?
      They are unreactive due to having a full outer shell
    • Which groups of elements gain electrons easily?
      Elements in groups 15-17
    • Hydrogen bonding occurs when an H atom covalently bound to one molecule forms a weak attraction with another electronegative atom such as N, O, or F.
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