3.1 The periodic Table Flashcards
How are the elements arranged in a periodic table?
They are arranged in the order of increasing atomic numbers
What is a period on a periodic table?
The horizontal rows in the periodic table
What is a group on a periodic table?
The vertical columns
Who’s table is the modern one based off
Dmitri Mendeleev
Why did Mendeleev leave gaps in his table?
left gaps where no element at the time fitted the repeating patterns. properties of these were predicted
What is meant by periodicity?
The repeating trends in chemical and physical properties
What change happens across each period?
Elements change from metals to non metals
How can the electron configuration be written in short?
The noble gas before (period above)the element is used to abbreviate
E.g Li → 1s22s1 ; Li → [He] 2s1
What are the S block elements?
groups 1&2
What are the D block elements?
transition metals(middle part)
What are the P block elements?
groups 5-8
Define first ionisation energy
The energy required to remove 1 mole electron from 1 mol of gaseous atom to form one mole of gaseous 1+ ions
Write an equation for the first ionisation energy
X(g)→X+ (g) + e-
What are the factors that affect ionisation energy?
- Atomic radius(further away=less attraction)
- Nuclear charge
- Electron shielding or screening (more shells= more shielding)
How does electron shielding work?
Inner electron shells repel the outer electron shells. Shielding ‘blocks’ nuclear attraction reaching outer shells