Module 3 Periodic Table and Energy
No description yet. This curated deck is ready for daily study.
Card preview (24)
Horizontal rows of elements
Periods
Vertical rows of elements
Groups
How are elements arranged in the periodic table?
In order of increasing atomic number
Defintion of periodicity
Repeating patterns of trends across different periods
Why do elements in a group have similar chemical and physical properties?
Because they all have the same number of outer electrons
There’s a ___________ ________ from metal to non-metal across each period
Periodic trend
True or false: Metals are good conductors of electricity
True
True or false: Non-metals are good conductors of electricity
False
True or false: Metalloids are non-conductors of electricity
False - they are poor conductors of electricity
Chemical reaction always involve the __________ _______
Outer shell
Elements in the same period contain a _________________ ________ of electrons
Common core
Explain why magnesium is an S-block element (1)
S-block elements have their highest energy outer-shell electron in an S-orbital
Explain trends in atomic radii across a period
• Protons added to nucleus so nuclear charge increases • Electrons added to the same shell • Nuclear attraction on outer shell electrons increases across a period • Electron shells are drawn inwards by nucleus, making atoms smaller Trend is: atomic radii decreases across a period from left to right
Explain trends in atomic radii down a group
• Number of shells increases • Outer electron is added to a new shell which is further away from nucleus • The shielding effect by inner shell electrons increases down a group • The increase in distance far outweighs the increase in nuclear charge • The nuclear attraction decreases down a group Trend is: atomic radii increases down a group
Giant substances have _____________ bonds, so _________ melting and boiling points
• Strong • High
Simple substances have ___________ bonds, so have ______ melting and boiling points
• Weak • Low
Describe the melting and boiling points across all the periods in the periodic table
• Increase gradually between groups 1 and 4 (metallic bonding) • Decrease sharply between groups 4 and 5 (simple covalent) • Are comparatively low between groups 5 and 8 (simple covalent)
What does ionisation energy produce, and how does it achieve this?
Produces ions with a positive charge by removing electron from outer shell
What is ionisation energy?
Energy required to overcome the ES force
Definition of first ionisation energy
The energy required to remove one electron from each atom in one mole of gaseous atoms to form one mole of gaseous 1+ ions
Write the first ionisation energy of oxygen
O(g) ——> O+(g) + e-
Which 3 factors affect first ionisation energy?
• Nuclear charge • Distance of outermost electron from nucleus • Electron shielding
Explain how nuclear charge affects first ionisation energy
• More protons = higher nuclear charge • Stronger nuclear attraction on outer electrons • More energy needed to overcome attraction between nucleus and outer electron
Explain how the distance from the outermost electron affects first ionisation energy
• As distance increases, attraction decreases • Weak nuclear attraction requires less energy to overcome