Periodic table Flashcards
What are the trends going down a group
- Atomic radii increases
- Atomic number increases
What are the trends going across a period
- Atomic number increases
- Metallic character decreases
- Oxide properties change
(Basic > Amphoteric > Acidic)
Define metallic character
Metallic character is the ability of an atom to lose valence electrons to form positive ions
What are G1 elements called
Alkali Metals
What are the physical properties of G1 elements
- Good electrical conductors
- Soft
- Shiny
- Low density
- Low melting points
What are the chemical properties of G1 elements
- Melting point decreases down the group
- Reactivity increases down the group
- React vigorously with oxygen to produce a metal oxide
- React vigorously with water to produce metal hydroxide + H2 gas
- React vigorously and burn brightly when heated with Cl2 to form metal chloride
- Basic in nature
- Behave as powerful reducing agents
- Carbonates are thermally stable
- Must be stored in oil
Why must G1 elements be stored in oil
Prevents the metals from becoming tarnished when reacting with oxygen and water vapour in air
Why does reactivity of G1 elements increase down the group
- Down the group, atomic radius increases
- Valence shell will be further from the nucleus
- There will be weaker electrostatic forces of attraction between the nucleus and valence electrons
- Smaller amount of energy is needed to remove valence electrons
- Valence electrons are lost more readily
- Reactivity increases down the grp
What are the physical properties of transition metals
- Good electrical conductors
- High melting and boiling points
- High density
What are the chemical properties of transition metals
- Exhibit variable oxidation states
- Form coloured compounds
- Act as good catalysts
Name some catalysts and their uses
Iron - Haber Process
Nickel - Margarine production
What are the physical properties of G17 elements
- Exist as diatomic molecules
- Elements are coloured
- Low melting and boiling points
- Electrical insulators
- Soluble in water
What are G17 elements called
Halogens
What is the colour od aqueous bromine
Orange
What is the colour of fluorine gas
Pale yellow
What is the colour of chlorine gas
Greenish-yellow
What is the colour of aqueous chlorine
Pale yellow
What is the colour of iodine gas
Purple
What is the colour of liquid bromine
Red-brown
What are the chemical properties of G17 elements
- Melting and boiling points increase down the group
- Reactivity decreases down the group
- Behave as powerful oxidising agents
- Undergo displacement reactions
- Can form both ionic and covalent compounds
Why do melting and boiling points of G17 elements increase down the group
- Size of halogen molecules increase down the group
- Greater surface areas of interaction between larger molecules
- More energy required to overcome strong intermolecular forces of attractions
Why does reactivity of G17 elements decrease down the group
- Down the group, atomic radius increases
- Distance between nucleus and valence shell increases
- Electrostatic forces of attraction between nucleus and valence shell are weaker
- More difficult for nucleus to attract an electron into the valence shell
- Electrons are gained less readily into valence shell
- Reactivity decreases down the group
How do G17 elements undergo displacement reactions
More reactive halogen will displace a less reactive halogen from its aqueous halide solution
What are the uses of some halogens
Chlorine used as a disinfectant and bleaching agent
What are G18 elements called
Noble Gases
What are the properties of G18 elements
- Monatomic
- Low melting and boiling pts
- Insoluble in water
- Chemically inert
Which Noble Gas does not have a stable octet configuration
Helium
What are some Noble Gases and their uses
Helium - Fill up balloons
Neon - Advertisement lights
Argon - Fill up light bulbs
Why must argon be used to fill up light bulbs
Provides an inert environment to protect tungsten filament from reacting with oxygen under high temperature
