The Periodic Table Flashcards
What is the periodic table?
The periodic table is a table that arranges the elements in a unique arrangement.
Where (roughly) are the metals found?
On the left (roughly)
Where (roughly) are the non-metals found?
On the far right
What are periods in the periodic table?
The rows (horizontal)
What are groups in the periodic table?
Columns (vertical), the elements in the same group usually have similar properties.
Characteristics of Alkali Metals
- Soft
- Melt at a lower temperature than most metals
- Highly reactive (and muse be stored under oil)
Which group are the Alkali Metals in?
Group 1
Alkali metal reaction with water?
They react vigorously with water. The chemical formula is:
_______ + water → _______ hydroxide + hydrogen
What is the trend in reactivity with the Alkali Metals?
The reactions become more vigorous as you descend down the group.
For example, Lithium’s (Li) reaction with water can be seen as just a small amount of effervescence, whereas Francium’s (Fr) reaction causes a very dangerous explosion.
What are the properties of metals?
- Shiny
- High melting points
- Good conductors of electricity
- Good conductors of heat
- High density
- Malleable (can be hammered/pressed into a new shape without breaking)
What are the properties of non-metals?
- Dull
- Low melting points
- Poor conductors of electricity
- Poor conductors of heat
- Low density
- Brittle (easily broken)
How to test for hydrogen in an alkali metal + water?
Using a lit splint:
1. Fill up a test tube partially with water.
2. Place a freshly cut portion of an alkali metal in the water.
3. Place a little splint over the test tube, and if you hear a squeaky pop then hydrogen is present.
What are the Group 1 Alkali Metals?
- Lithium (Li)
- Sodium (Na)
- Potassium (K)
- Rubidium (Rb)
- Caesium (Cs)
- Francium (Fr)
Lithium (Li) observations
- Appearance: Black, dull (non-shiny) solid
- Appearance when freshly cut: Shiny, grey, solid, soft
- Hardness: Soft
- Observations with water: effervescence, hydrogen gas burning → smoke, vigorous
- When universal indicator is added: blue → purple
- Lit splint test: squeaky pop, ignite
- Products: lithium hydroxide and hydrogen
Sodium (Na) observations
- Appearance: White, solid
- Appearance when freshly cut: Shiny, soft
- Hardness: Softer than Li
- Observations with water: Melted into a ball → hot, hydrogen gas burning → smoke, heated, more vigorous
- When universal indicator is added: Leaves a purple trail (sodium) when more [sodium] is added
- Lit splint test: squeaky pop, ignite
- Products: sodium hydroxide and hydrogen