C2 - The Periodic Table Flashcards
How are elements arranged in today’s periodic table?
In order of atomic(proton and electron) number
Why is the periodic table called this?
Elements with similar properties occur at regular intervals
Why do elements in the same group have similar properties?
They have the same number of electrons in their outer shell
How was the early periodic table arranged?
In order of atomic weight
What were the problems with the arrangement of the early periodic table?
- Not all elements discovered
- When placed in order of atomic weight, they ended up in the same group
What did Mendeleev do?
- Left gaps for undiscovered elements and changed order of some elements
- So properties fitted other elements in the same group
Why was his periodic table used?
- New elements were discovered that matched these gaps he predicted
- Discovery of neutron led to an understanding of isotopes which explained why he had to swap positions of elements
Explain the arrangement of the first 20 elements
- Arranged in order of their atomic number
- Elements in the same group have the same number of electrons in their outermost shell
What ions do metals form and where are they found?
- Positive
- Left side
What ions do non-metals form and where are they found?
- Negative
- Right side
What are specific properties of transition metals?
- Can form more than one ion
- Compounds which contain them are colourful
- Often make good catalysts
What are the properties of Group 0 Noble gases?
- Unreactive = atoms have a stable arrangement of electrons(full shell)
- Monatomic = have a full shell so don’t gain or lose electrons
What happens to the boiling and melting point down Group 0?
- Increases
What happens to the density down Group 0?
- Increases
What are the properties of the Group 1 alkali metals regarding reactivity?
- Reactivity increases down the group
- Down the group atoms get bigger
- weaker attraction between nucleus
- becomes easier to lose electrons
What happens to the melting point down Group 1?
- Decreases down group
What happens to density down Group 1?
- Increases down group
What are the products of alkali metal+oxygen?
- Metal Oxide
What are the products of alkali metal+chlorine?
- Metal chloride
What are the products of alkali metal+water?
- Metal Hydroxide+Hydrogen
Why do Group 1 metals have similar properties?
Because of their single electron in the outermost shell
What are the properties of the Group 7 halogens regarding reactivity?
- Reactivity decreases down the group
- Down the group atoms get bigger, outer shell is further away from nucleus
- More shells between nucleus and outer shell
- Weaker attraction between nucleus and it becomes harder to lose electrons
What happens to the melting point down Group 7?
- Increases
What happens to density down Group 7?
- Increases down group
Why do Group 7 halogens have similar properties?
- Because they have 7 electrons in their outer shell
What is the difference between the melting points in transition and group 1 metals?
Higher melting points in transition metals
What is the difference between the densities in transition and group 1 metals?
More dense in transition
What is the difference between the strength in transition and group 1 metals?
Transition stronger
What is the difference between the hardness in transition and group 1 metals?
Transition harder
What is the difference between the reactivity in transition and group 1 metals?
Transition less reactive
