Main Group Chemistry Flashcards
What are the main group chemistry blocks?
s and p
Which elements are anomalous in their behaviour?
second period
Which elements are representative of their group?
third period
What are the reasons for the anomalies?
1) Small size and high electronegatively
2) Maximum of four covalent bonds (no d orbitals for bonding)
3) More common occurrence of multiple bonding (good pie overlap of 2p orbitals)
Why do elements within the same group exhibit similar behaviours?
Because of the similar valence electron configurations
Group 13 name?
Triels
Group 15 name?
Pnictogens
Group 16 name?
Chalogens
What kind of behaviour increases as down a group
metallic
Which element does not have a perfectly suitable position in the periodic table?
Hydrogen
What properties does hydrogen have?
Very reactive and combines with nearly every other element
What unique properties does alkali metals have?
- usually soft
-Lower melting and boiling points and densities compared to other metals
What is the hydride ion (H-) powerful at?
Being a reducing agent
What metal reacts vigorously in water?
Potassium
Alkali metals are ______ reactive and are powerful ___________ agents
extremely
reducing
In what kind of reactions does alkali metals reduce halogens
highly exothermic reactions
What properties does alkaline earth metals have?
- harder and higher melting points
- somewhat less reactive
What is the use of CaCO3?
- heated to obtain calcium oxide (lime)
- lime has essential roles in steelmaking, water treatment, and smokestack scrubbing
- lime is used to make glass, whiten paper, and neutralize acidic soil
How is Be a unique alkaline earth metal?
- un-reactive in air and water
- BeO is an amphoteric oxide (can act as an acid or a base in a reaction)
- Be compounds have strong covalent character AND conduct electricity poorly in the molten state
What is cesium used for?
- in atomic clocks
- photovoltaic cells
- night vision equipment
What is strontium used for?
- used in fireworks
- in signal flares
What is Be and Mg used for?
- used in manufacture of alloys
- Mg- Al alloys are used in the construction of aircrafts
What is barium used for?
- Barium sulfate is used in x rays to detect problems in the digestive tract (insoluble in water - coats the esophagus, stomach, and intestines)
- Barium nitrate and barium chlorate are used in fireworks
- used in paint pigments
Boron description
- metalloid
- has a covalent network structure
- is black, hard and high melting point
