1.4 Trends in the Periodic Table Flashcards
(20 cards)
What is the trend of metallic character?
As you go along the table, metallic character decreases. As you go down the table, metallic character increases.
What are some physical properties of metals?
- Solids with high melting/boiling points (except Hg)
- Malleable and ductile
- Good conductors of heat and electricity
- Usually lustrous and can be polished
- Sonorous - gives of sound when hit
- Usually high densities
- Not brittle - can withstand stress and strain
What are some physical properties of non-metals?
- Low melting/boiling points (some expectations) and are usually gasses or liquids
- Not malleable or ductile
- Poor conductors (except graphite)
- No lustre and cannot be polished
- Not sonorous
- Lower densities than metals
- Brittle and break easily when under stress
What are some chemical properties of metals?
- They lose electrons to become positive ions (cations)
- Mainly form ionic compounds
What are some chemical properties of non-metals?
- Gain electrons to become negative ions (anions)
- Mainly form covalent compounds
What are the characteristics of metalloids?
Display metal and non-metal characteristics
What are the properties of alkali metals ?
- react with water to form alkaline solutions
- low melting points
- low boiling points
- low density
- very soft (can be cut with a knife)
- very reactive
What group are Alkali metals?
Group 1
What group are alkaline Earth metals?
Group 2
What are the properties of alkaline Earth metals?
- less reactive than group one/alkali metals
- 1st extracted from oxides found in Earth’s crust
What group are halogens?
Main group 7 or 17
What are the properties of halogens?
- So reactive that they never occur free in nature
- combines with metals to form salts
What group are the nobel gases?
Main group 8 or 18
What are the properties of nobel gases?
- Don’t react readily with other substances
- All colourless gases
- Low melting and boiling points
- single atoms
What is valency?
The number of electrons added, removed or shared by an atom when combined with another atom
What is atomic radii?
The average distance from the center of the nucleus to the boundary of the valence shell
What is the trend of atomic radii?
As you go down, the atomic radii increases, as you go across the atomic radii decreases
What is electronegativity?
A measure of an elements tendency to attract electrons from other atoms
What is electronegativity measured in?
Pauling units, from 0.7 to 4.0
What is the trend of electronegativity?
As you go down, it decreases, as you go across, it increases
