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Flashcards in Chemistry of the Elements Deck (18)
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1
Q

What are the group 1 metals?

A
  • the alkali metals

- all have one electron in their outermost shell, making them very reactive

2
Q

What happens when lithium, sodium and potassium react with water?

A
  • they react more vigorously as you go down the group, produced a metal hydroxide solution that is alkaline
  • also produces hydrogen
  • lithium fizzes and moves slowly
  • sodium moves rapidly, may ignite
  • potassium burns with a lilac flame
3
Q

How does the rate of reaction change going down the group 1 metals?

A
  • the elements become more reactive
4
Q

Why are elements with higher atomic number in group 1 more reactive?

A
  • all group 1 metals have 1 electron in their outer shell
  • as you go down group 1, the outermost electron is in a shell that’s further from the nucleus
  • which means the attraction between the outermost electron and the nucleus becomes less
  • so as you go down group 1, the atoms get bigger, the outer electron is more easily lost and the metals are more reactive
5
Q

What are group 7 elements called?

A
  • halogens
6
Q

What are the properties of chlorine, bromine and iodine?

A

Chlorine:

  • green
  • gas at room temperature
  • boiling point: -34 degrees celsius

bromine:

  • red-brown
  • liquid at room temperature
  • boiling point: 59 degrees celsius

iodine:

  • dark grey
  • solid at room temp
  • boiling point: 185 degrees celsius
7
Q

What happens as the atomic number of the halogens increase?

A
  • the elements have a dark colour

- a higher boiling point

8
Q

Are the elements more reactive higher or lower in group 7 and why?

A
  • the higher an element is, the more reactive it is

- the shell with the missing electron is nearer to the nucleus, so the pull from the positive nucleus is greater

9
Q

What forms when halogens combine with hydrogen?

A
  • hydrogen halides
10
Q

What is hydrogen chloride?

A
  • HCl

- gas at room temp

11
Q

What happens when hydrogen chloride is dissolved in water?

A
  • the molecules split up into H+ ions and Cl0 ions
  • a process called dissociation
  • forming hydrochloric acid
12
Q

Why is hydrochloric acid acidic but not hydrogen chloride?

A
  • it contains H+ ions

- you can test with blue litmus and it will turn red

13
Q

What if you dissolved HCl in methylbenzene?

A
  • it does not dissociate, so it is not acidic

- blue litmus paper will stay blue, unless there is moisture on the paper or bottle

14
Q

What is a displacement reaction?

A
  • a displacement reaction is where a more reactive element displaces (pushed out) a less reactive element from a compound
15
Q

What is a redox reaction?

A
  • where oxidation and education happen at the same time

- displacement reactions are always redox reactions

16
Q

What is the oxidising agent?

A
  • accepts electrons and gets reduced
17
Q

What is the reducing agent?

A
  • donates electrons and gets oxidised
18
Q

Explain the relative reactivates of group 1 elements in terms of distance between outer electrons and the nucleus

A
  • all group 1 metals have an electron in their outer shell
  • as you go down group 1, the outermost electron is in a shell that’s further away from the nucleus
  • so the attraction between the outermost electron and nucleus becomes less
  • as you go down the group, atoms become baggers o outer electron is more easily lost and metals are more reactive