Atomic structure + the periodic table

• Who proposed that matter is made of atoms in 1803?

  Dalton
• What did Thomson discover and what model did he propose?

  Thomson discovered electrons and proposed the plum pudding model.
• What experiment did Rutherford conduct and what was the outcome?

  Rutherford fired alpha particles at thin gold foil, most went through, but some bounced off, leading to the nuclear model.
• What is the charge of the nucleus according to Rutherford's model?

  The nucleus is positive.
• According to Bohr, how do electrons behave in an atom?

  Electrons orbit the nucleus in shells.
• Who discovered neutrons and where are they located?

  Chadwick discovered neutrons, which are located in the nucleus.
• What are the key features of the Plum Pudding Model?

  • Ball of positive charge
  • Electrons embedded within
• What are the key features of the Nuclear Model?

  • Electrons in shells
  • Nucleus contains protons and neutrons
  • Most of the atom is empty space
• What is the mass number of an atom?

  The mass number is the total number of protons and neutrons.
• What is the atomic number of an atom?

  The atomic number is the number of protons (also electrons).
• What are isotopes?


  Isotopes are atoms with different numbers of neutrons but the same atomic number.
• What is relative atomic mass?

  Relative atomic mass is the weighted average of the masses of isotopes.
• Why is relative atomic mass usually not a whole number?

  Relative atomic mass is usually not a whole number because it is a weighted average of isotopes.
• What did Dmitri Mendeleev contribute to the periodic table?

  • First periodic table in 1869
  • Elements ordered by increasing atomic weight
  • Identified properties of elements
  • Left gaps for undiscovered elements
• What is the modern periodic table organized by?

  The modern periodic table is organized by increasing atomic number.
• What are the characteristics of groups in the periodic table?

  • Columns called groups
  • Elements in the same group have similar chemical properties
• What are the characteristics of periods in the periodic table?

  Rows are called periods, and they indicate the number of electron shells.
• How many electrons can the first shell hold?

  The first shell can hold 2 electrons.
• How do metals and non-metals differ in terms of electron behavior?

  Metals lose electrons to form positive ions, while non-metals gain electrons to form negative ions.
• What are the properties of metals?

  • Conduct electricity and heat
  • Shiny appearance
  • High density
  • Malleable (bendy)
• What are the properties of non-metals?

  • Poor conductors of electricity and heat
  • Dull appearance
  • Low density
  • Brittle
• Where are metals and non-metals located on the periodic table?

  Metals are on the left, and non-metals are on the right.
• What is the Nuclear Model?

  • Electrons are negatively charged
  • Protons and neutrons are located in the nucleus
  • The atom consists mostly of empty space
• What are the relative masses and charges of protons, neutrons, and electrons?

  • Proton: Relative Mass = 1, Relative Charge = +1
  • Neutron: Relative Mass = 1, Relative Charge = 0
  • Electron: Relative Mass = Very small (0), Relative Charge = -1
• What are the features of the modern periodic table?

  • Rows are called periods and represent increasing atomic number
  • Columns are called groups and represent similar properties
• What is the maximum number of electrons in the second shell of an atom?

  The maximum number of electrons in the second shell is 8.
• How is the number of shells related to the periodic number?

  The number of shells corresponds to the periodic number of the element.
• How is the group number related to the number of electrons in the outermost shell?


  The group number indicates the number of electrons in the outermost shell.
• What happens to metals in terms of electrons?

  Metals lose electrons to form positive ions.
• What happens to non-metals in terms of electrons?

  Non-metals gain electrons to form negative ions.
• What are the general properties of metals and non-metals?

  Metals:

  • Conduct electricity and heat
  • Shiny appearance
  • High density
  • Malleable (bendy)

  
  

  Non-metals:

  • Poor conductors of heat and electricity
  • Dull appearance
  • Low density
  • Brittle
• What are the characteristics of Group 0 (Noble Gases)?

  • Low boiling points, with helium having the lowest
  • Atoms are larger going down the group
  • Extremely unreactive (inert)
  • Full outer shell of electrons
• What are the characteristics of Group 1 (Alkali Metals)?


  • Soft and can be cut with a knife
  • Relatively low boiling points and densities
  • One electron in the outer shell, which they lose to form positive ions