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Flashcards in C4 Deck (19):
1

How many elements were known in 1800?

30

2

What is relative atomic mass?

It is the mass of an element compared to the lightest element hydrogen

3

who formulated the idea of the modern periodic table?

Dmitri Mendeleev

- he listed elements in order of relative atomic mass, and also left gaps for undiscovered elements in his table. He also noticed that at intervals along the ordered elements were elements with similsr properties e.g. lithium, sodium,potassium share properties

4

What is the modern periodic table?

5

What is a general formula equation for group 1 elements reacting with chlorine and how does this reaction occur

-alkali metal +chlorine=salt

the matl burns in the gas producing different colured lights

-leaves colourless precipitate(salt)

6

What are some compounds of alkali metals?

sodium hydroxide(oven cleaner)

sodium hydrocarbonate

bicarbonate of soda, used in baking

7

Why are Group 1 metals called alkali meatl?and what are their properties?

 

as they leave an alkali solution when reacting with water

-corrosive, highly flammable

-very reactive

-reacts with air so kept in oil

-soft metals

-very shiny

-conduct electricity

-less dense then normal metals

8

What is the foemula equation for an alkali metal reacting with water?

alkali metal+water=hydrogen+an alkali metal hydroxide

9

What happens to the reactivity of metal as you go down the period in Group 1

It increases

10

What are the properties of Group 7 elements?

-all very reactive non-metals

-known as halogens

-all diatomic

low melting point , high boiling point

forces between molecules is weak

melting and boiling points as yo go down the table

11

What are the properties of chlorine,Bromine and iodine?

12

What are some uses of halogens?

chlorine is used as bleach

clean water

florine is toothpaste

iodine to clean wounds

13

What happens to reactivity of halogens as you go up the periods?

It increases

14

What is a displacement reaction?

This where a more reactive halogen replaces the other halogen to form a new compound

15

HoW can unknown elements be identified?

By burning them and seeing the flame they produce

16

What was Dalton's theory about atoms?

every element has its own atoms that differ in mass

no atom can be created or destroyed

17

How many electrons can each shell hold?

2,

8

18

18

What is a general rule to tell if a element is a metal or not?

elements with more than two electrons are generally gases

otherwise they are metals

19

What are some ions in the periodic table?