C1 atomic structure

• What are atoms the smallest part of?

  An element
• What does the chemical symbol Na represent?

  An atom of sodium
• How are compounds formed?

  By chemical reactions between elements
• What do chemical reactions involve?

  Formation of new substances and energy change
• How many elements are in a compound?

  Two or more
• How can compounds be represented?

  By formulae using chemical symbols
• How are elements arranged in the periodic table?

  By atomic (proton) number
• How can compounds be separated?

  Only by chemical reactions
• What is the significance of groups in the periodic table?

  Elements in groups have similar properties
• What do elements in the same periodic group share?

  The same number of outer shell electrons
• Who ordered the early periodic table by atomic weight?

  John Newlands
• What is a mixture?

  Two or more substances not chemically combined
• What did John Newlands discover about element properties?

  Similar properties occurred every eighth element
• What limitation did Newlands' law of octaves have?

  It broke down after calcium
• How did Mendeleev arrange his periodic table?

  By atomic mass, but not strictly
• What did Mendeleev do for undiscovered elements?

  He left gaps for them in his table
• What happens to the chemical properties in a mixture?

  They remain unchanged
• Why is it called a periodic table?

  Because similar properties occur at regular intervals
• What was discovered that confirmed Mendeleev's predictions?

  Elements with predicted properties were discovered
• What processes can separate mixtures?

  Filtration, crystallisation, distillation, chromatography
• How did isotopes affect the periodic table's arrangement?

  They explained order based on atomic weights
• What particles were discovered in the early 20th century?

  Electrons, protons, and neutrons
• What type of processes are used to separate mixtures?

  Physical processes
• How are elements ordered in the modern periodic table?

  By atomic (proton) number
• Where are metals located in the periodic table?

  To the left and bottom of the table
• What do metals form when they react?

  Positive ions
• Where are non-metals found in the periodic table?

  Towards the right and top of the table
• What was the first model of the atom thought to be?

  Tiny spheres that could not be divided
• What is a characteristic property of alkali metals?

  Single electron in their outer shell
• What do alkali metals produce when they react with oxygen?

  Oxides
• How do alkali metals react with water?

  They create an alkaline solution and hydrogen
• What do alkali metals form when they react with chlorine?

  A white precipitate
• How does reactivity change in group 1 elements?

  Reactivity increases going down the group
• How does lithium react with oxygen?

  Burns with a red-tinged flame
• How does sodium react with water?

  Fizzes rapidly and melts into a ball
• How does potassium react with chlorine?

  Produces a lilac flame and disappears quickly
• How many electrons do noble gases have in their outer shell?

  Eight electrons, except helium
• Why are noble gases unreactive?

  They have a stable arrangement of electrons
• How do boiling points change in noble gases?

  They increase with atomic mass down the group
• What do halogens have in common regarding their outer shell?

  They have seven electrons in their outer shell