groups in the periodic table Flashcards
What is the charge and mass on a proton, neutron and electron?
proton: 1, 1
neutron: 0, 1
electron: -1, 1/2000
What are the properties of Alkali metals?
- form alkaline solutions when they react with water
- reactivity increases as you go down
- soft
- low densities & boiling points
What does an alkali metal + water make?
Metal hydroxide + hydrogen
What are the properties of halogens?
- nonmetals
- poisonous
- diatomic (exist in pairs)
- boiling points increase as you go down
What is the test for chlorine?
Use litmus paper, if chlorine has in present then damp, blue litmus paper will be bleached white.
What does a halogen and sodium make?
Salt.
What are halides?
When halogens react with another substance they become negative ions (end in ide)
What is a displacement reaction?
When a more reactive element displaces a less reactive element from a compound.
A more reactive halogen will always displace a less reactive halide.
What’s the method to test for the reactivity of alkali metals?
- fill water trough with cold water
- place piece of lithium in water
- observe reaction
- test water with universal indicator
What’s the method for displacements of halogens?
- Add few drops of chloride water to a spot on laminated sheet
- Add few drops of potassium chloride to same spot
- write colour change down
- repeat for others
What is oil rig?
Oxidation is loss, reduction is gain
What is reduced and gained in a displacement reaction?
Halogen - halide = reduced
Halide - halogen = oxidised
What are the properties of noble gases?
- colourless gases at room temp
- unreactive/inert
- low melting and boiling points (increase as you move down)
- low densities (increase as you move down)
