Lecture 3-The periodic table Flashcards
1
Q
Alkali metals
A
- Silver coloured
- Soft
- Highly reactive + rarely found naturally
- Small n.o of e- —-> weak bonds
2
Q
Alkaline earth metals
A
- Silver coloured
- Soft
- Similar reactivity to alkali
3
Q
Transition metal definition
A
“An element with at least one oxidation state that has a partially filled d-subshell”
4
Q
Transition metals
A
- High densities
- High mp + bp
- Form colour compounds
- Form complex ions
- Valences = variable
- Ions - readily undergo oxidation / reduction
5
Q
Lathanides
A
- 15 elements with atomic number 57-71
- Shiny
- Silvery-white
- Stain easily when exposed to the air
- High mp + bp
6
Q
Actinides
A
- 15 elements with atomic number 89-103
- Radioactive
- Very dense metals
- Numerous allotropes e.g. plutonium = 6
- Combine directly with most non-metals
7
Q
Noble gases
A
- Chemically inert
- Non-metallic
- Gaseous (at standard conditions)
8
Q
Halogens
A
- Highly reactive
- Toxic
- F + Cl = gases
- Br = low bp
- I = melting materials
9
Q
Metalloids
A
- 6 elements
- Properties of both metals + non-metals
- Semi-conductors
10
Q
Why do metalloids have non-metal properties?
A
Covalent bonds
11
Q
Non-metals
A
- Not able to conduct
- Very brittle
- Can’t be rolled into wires / pounded into sheets
- O = gas
- C = solid
- Br = liquid
- No metallic lustre
- Doesn’t reflect light
12
Q
What are the general characteristics of properties of elements?
A
All the elements of a given group possess very similar physical + chemical properties, with a regular graduation in their properties moving from top —> bottom (in a group)
13
Q
Size of atoms
A
INCREASES down a group
14
Q
Metallic character
A
INCREASES down a group
