Chemistry Paper 1 Combined

• What are all substances made from?

  Elements
• What is the smallest part of an element that can exist?

  An atom
• Approximately how many different elements are there?

  100
• Where are all of the elements shown?

  The Periodic Table
• What are formed from elements by chemical reactions?

  Compounds
• What do chemical reactions always involve?

  The rearrangement of atoms
• What is the definition of substances containing two or more elements chemically combined in fixed proportions?

  Compound
• What is the definition for something consisting of two or more elements or compounds not chemically combined together?

  Mixture
• Which processes can be used to separate mixtures?

  • Filtration
  • Crystallisation
  • Distillation
  • Chromatography
  • Fractional Distillation
• Before the discovery of electrons, what were atoms thought to be?

  Tiny spheres that could not be divided
• What is the model that was discovered regarding atomic structure?

  Plum pudding model
• What does the plum pudding model suggest about atoms?

  Atoms are made of a positive 'soup' with negative electrons embedded in it
• What did the results of Rutherford's alpha scattering experiment show?

  Atoms have a small, dense nucleus
• How did Niels Bohr improve the model of the atom?

  By introducing quantized energy levels for electrons
• What did the experiment carried out by Chadwick provide evidence for?

  The existence of neutrons
• What is the name given to a positively charged particle?

  Proton
• What is the relative charge of a proton?

  +1
• What is the relative charge of a neutron?

  0
• What is the relative charge of an electron?

  • 1
• What is the radius of an atom?

  Approximately 0.1 nm (1 x 10^-10 m)
• How many times smaller is the radius of the nucleus compared to the atom?

  About 10,000 times smaller
• What is the relative mass of a proton?

  1
• What is the relative mass of a neutron?

  1
• What is the mass number of an atom?

  The sum of the protons and neutrons
• What do we call atoms of the same element with different numbers of neutrons?

  Isotopes
• What are the key components of an atom and their relative masses?

  • Proton: relative mass = 1
  • Neutron: relative mass = 1
  • Electron: relative mass ≈ 0.0005
• How does the size of an atom compare to its nucleus?

  • Atom radius: ~0.1nm(1x10^-10m)
• What do isotopes of an element have a different number of?

  Neutrons
• What is the relative atomic mass of an element?

  The average values of the abundance of the isotopes of the element
• What is the maximum number of electrons that can be found on the lowest energy level?

  2
• What is the maximum number of electrons that can be found on the second energy level?

  8
• How are the elements in the periodic table arranged?

  In order of atomic number
• What do we call a column in the periodic table?

  Groups
• What do we call rows in the periodic table?

  Periods
• What do elements in the same group in the periodic table have in common?

  The same number of electrons in their outer shell
• Before the discovery of protons, neutrons, and electrons, how did scientists classify the elements?

  Arranging them in order of their atomic weights
• How did Mendeleev overcome problems with creating a periodic table?

  By leaving gaps for undiscovered elements
• What are elements that react to form positive ions called?

  Metals
• What are elements that do not form positive ions called?

  Non-Metals
• What is the majority of elements classified as?

  Metals