Topic 1b- Periodic elements (Paper 1 + 2) Flashcards
(30 cards)
What is the word for a positively charged ion?
Cation
What is the word for a negatively charged ion?
Anion
What is a group and what do all the members have in common?
A group is a vertical column in which elements share the same number of electrons in their outer shell.
What is a period and what do the members of the period have in common?
A period is a horizontal column in which elements have the same number of electron shells and therefore have similar chemical properties.
What is another name for group 1 elements?
Alkali metals
What is another name for group 2 elements?
Alkali earth metals.
What are the physical properties of alkali metals?
Soft metals that can be cut with a knife.
Lower density.
As you go down the group the melting points become lower.
Why are group one metals kept in oil?
To prevent them from reacting with the surrounding air.
Why does reactivity increase when going down the group 1 elements?
As you go down the group:
The outer electron is further away from the positive nucleus causing weaker attraction.
There are more shielding inner shells
—> less attraction between outer electrons and nucleus causing them to be easily lost —> more reactive.
What do all group 1 compounds have in common?
White when solid.
Soluble in water.
Colourless when in solution.
What is oxidation?
When an element looses electrons.
What is reduction?
When an element gains electrons.
What type of bonding happens between halides?
Covalent.
What is a halide?
Compound of a halogen and a non-metal.
Give the other name for group 7 elements.
Halogens.
List the physical properties of group 7 elements.
Diatomic molecules.
Low boiling points.
Low melting points.
More reactive as you go up the group.
What is the trend in melting and boiling points of group 7 elements?
Both are low.
What is the charge of a halide ion?
-1
Explain why elements become less reactive as you go down the halogens?
There are more shells shielding the positively charged nucleus as you go down the group causing weaker forces of attraction to the nucleus.
What are the properties of noble gases?
Full outer shells.
Very unreactive.
Group 0.
What is the trend of boiling points and densities in the noble gases?
They increase as you go down the group.
What are the properties of noble gases at room temperature?
Colourless, gas, monatomic.
Define monatomic.
Travel as one atom, not as molecules. (e.g He vs O2)
How do the forces of attraction between noble gases change?
As you go down the group, the outer shell of electrons have less attraction to the positive nucleus due to more shells shielding, and therefore are more reactive since they have greater attraction to other molecules.
