Periodicity

• In what order are the elements arranged n the periodic table


  Increasing atomic number
• Where are the metals located on the periodic table


  On the left
• Where are the non-metals located on the periodic table

  On the right
• What is the name for elements that touch the staircase line separating non-metals and metals

  Metalloids
• Who was the creator of the final version of the periodic table

  Dmitri Mendeleev
• When was the final version of the periodic table released 


  1869
• What are the four blocks of the periodic table

  s, p, d, f
• What groups make up the s-block of the Periodic table

  1, 2
• What groups make up the p-block of the Periodic table

  3, 4, 5, 6, 7, 0
• Define the groups of the periodic table

  A group is a vertical column of elements
• How many groups are there excluding transition metals

  8
• How many groups are there including the transition metals

  18
• What is the trend in reactivity going down the s-block

  They get more reactive going down the group
• What is the trend in reactivity going down the p-block

  They get less reactive going down the group
• What are the only two naturally occurring radioactive metals

  Thorium and Uranium
• Define the periods of the periodic table

  Horizontal rows of elements
• What structures do groups 1, 2, and 3 on period 3 make

  They make giant ionic lattices
• What structure does silicon make

  It has four electrons so forms a macromolecular structure
• What do groups 5 , 6, and 7 in period 3 make

  They form simple covalents
• Why does group 0 in period 3 not react

  Argon has a full outer shell
• What is the trend in melting point from sodium to silicon in period 3

  Increasing
• What is the highest melting point simple covalent period 3 molecule and why

  Sulfur has the highest melting point as its formula is S8
• What has the lowest melting point in period 3

  Argon
• What is the atomic radii


  The distance is taken to be half the distance between the centers of a pair of atoms
• What is the trend in atomic radii going across period 3

  Decreasing
• Why does atomic radii decrease going across period 3

  Whilst the electron shielding remains constant the charge of the nucleus increases from 11+ to 17+, this charge increase pulls the elcrons closer to the nucleus,
• Why does radii of atoms increase going down a group

  There is one more main level of electrons
• Define first ionisation energy

  The energy required to convert one mole of gaseous atoms into a mole of 1+ gaseous ions.
• What is the general trend in first ionisation energy across a period

  Increasing
• In period 3 what are the two anomalies to the general trend of increasing first ionisation energy across the period

  Aluminum and Sulfur
• Why does the first ionisation energy increase across a period

  As you go across a period from left to right, the number of protons in the nucleus increases but the elctrons enter the same main level. The increased charge on the nucleus means that it gets increasingly difficult to remove an electron
• Why does the first ionisation energy decrease going don a group

  The number of filled inner levels increases down the group. This results in an increase in shielding. Also, the electron to be removed is at an increasing distance from the nucleus and is therefore held less strongly. thus the outer electrons get easier to remove going down a group because they are further away from the nucleus.
• What happens to the nuclear charge of atoms as you go left to right across a period

  Increases
• Why is there a drop in first ionisation energy between group 2 and 3 in period 3

  Magnesium 1s1, s2s, 2p6, 3s2 loses a 3s electron

  Aluminium 1s1, 2s2, 2p6, 3s2, 3p1 loses the 3p electron

  The p-electron is already in a higher energy level than the s-electron so it takes less energy to remove it.
• Why is there a drop in first ionisation energy between groups 5 and 6 in period 3


  Phosphorus has no paired electrons in a p-orbital. Sulfur, however, has two of its p-electrons paired so it is easier to remove than an unpaired one due to the repulsion of the other electron in the same orbital.
• What is the symbol for the electrons present in the orbitals


  two arrows point in oposite directions, up and down