periodic table

Question 1

issues w periodic table is the 19th cent

Answer 1

• elements were being discovered yearly
• scientists wanteed to find patterns in these elements

Question 2

john daltons ideas in periodic table

Answer 2

-published a table of elements
-ordered eliments by their atomic weight

Question 3

john newlands ideas

Answer 3

• arranged like dalton elements based on weight
• noticed the similarity of every eighth element so produced the law of octaves
• this did not work as he did not consider that elements were yet to be discovered, so a lot of the eigths werent actually alike

Question 4

menedeleevs discovery

Answer 4

• he ordered them by mass, but put them in collums based on similartiies
• he left gaps for and predicted elements that had not yet been discovered

Question 5

mendeleevs problem with irregular elements

Answer 5

• some elements like argon were heavier than potassium, but was clearly not a group oe metal as it was unreactive
• scientists later realised isotopes were the reason and so only grouped based off of their atomic number

Question 6

properties of alk metals

Answer 6

• very reactive as one outer shell electron
• reactivity increases as you go down the group as it means theyre less attracted to the neucleas and so the one electron can more easily leave
• fairly undense, soft and shiny when cut
• react v quickly with oxygen in air so dont stay shiny
• realativly low melting and boiling points

Question 7

alk metals reaction w water

Answer 7

-first three; float on the water and move around fizzing
- poassium burns w a lilac flame
- produces a hydroxide (alkaline)
- high ph

Question 8

properties of halogens

Answer 8

• low melting and boiling points
• poor conductors
• diatomic
• very reactive
• get less reactive goig down becasue they need to gain an electron and the more shells the weaker the pull of the nucleas

Question 9

displacement reactions w halogeons

Answer 9

• a more reactive - higher up the group- will displace a less reactive from its salt

Question 10

what does gaining/ losing the outer shell depend on

Answer 10

• outer shells distance from the attractive force of the nucleas
• shielding effect of the iner shells that reduce attraction

Question 11

what does inert mean

Answer 11

unreactive

Question 12

special traits of transition metals

Answer 12

• can form more than one ion, eg copper can be 1+ OR 2+
• CAN be coloured
• good catalysts