C2 The Periodic Table Flashcards
What are metals in the peroidic table?
Elements that react to form positive ions
Before the discovery of sub-atomic particles, how did scientists attempt to classify elements?
In order of their atomic weights
What were the problems of Newland’s arrangment of the periodic table?
- Gaps weren’t left for undiscovered elements
- His ‘Law of Octaves’ broke down after Calcium (Ca)
What was Newland’s Law of Octaves?
Every eighth elements ordered in atomic weight had similar properties
What was Mendeleev’s Breakthrough?
- ordered them in atomic weight but arranged them in a periodic pattern to similar properties in them
- left gaps for undiscovered elements
- predicted elements with properties that’d fit in those gaps
What is Group 0
Noble gases, stable atoms as they have a full outer shell
What are the Reactive metals and what are their properites?
Group 1 and Group 2
- React vigorously with other elements and water
- Soft and easily to cut
Properties of Alkali Metals:
- Good thermal conductors
- Good electrical conductors
- Lustre (having a shining apppearnce)
- Ductile
- Malleable
- React with water
Going down the table Group 1 elements boiling and melting points :
Decrease
Properties of Group 7 (Halogens) :
- Exist as diatomic molecules
- All form acids when reacted with hydrogen
- Combine with metals to form salts
- Form a negative ion
What is the trend in Group 1?
Reactivity increases as you go down the table
What is the trend in Group 7 (Halogens) :
Reactivity decreases as you go down the table
Physical Properties of the Transition Elements:
- Good conductors of physical and thermal energy
- They are hard and strong
- They have high densities
- They have high melting points (Except Mercury)
Chemical Properties of the Transition Elements:
Less reactive than alkali metals with oxygen, water or chlorine
What state is hydrogen at in room temperature?
Gas
