Atomic models

Question 1

What did Democritus propose in 400 b.c?

Answer 1

That matter is made of small molecules that can get infinitely tinier

Question 2

What was John Dalton’s contribution in 1803?

Answer 2

Developed on Democritus’ idea and suggested that matter was made up of tiny indivisible particles called ‘atoms’ and suggested that they combined in fixed rations - a key concept in modern chem

Question 3

What did JJ Thomson’s model of the atom look like in 1897?

Answer 3

He proposed the ‘Plum Pudding’ model of the atom which is a ball of negative charge with positively charged electrons inside it.

Question 4

How did Rutherford contribute?

Answer 4

He performed the ‘gold leaf’ experiment where he shot alpha particles at a piece of gold foil and wrote down where the particles went. This allowed him to confirm the existence of a nucleus that was positive as opposed to the plum pudding idea.

Question 5

Bohr 1913 what did he change about the atom?

Answer 5

He suggested the ‘Bohr model’ where there is a nucleus of protons and neutrons and electrons orbit the nucleus.

Question 6

1932 - Chadwick

Answer 6

Helped clarify the structure of the atom

Question 7

What are properties of group 1 elements?

Answer 7

Silver coloured,
Soft - easy to cut,
Dulls due to contact with oxygen (oxidation)
Highly reactive

Question 8

What mnemonic can be used to remember diatonic particles?

Answer 8

Have - hydrogen
No - nitrogen
Fear - fluorine
Of - oxygen
Ice - iodine
Cold - chlorine
Beer - bromine

Question 9

Characteristics of Lithium reacting with water (group one element)

Answer 9

Fizzing, smoking, makes the water alkaline pH, bubbles, floats

Question 10

Characteristics of Sodium reacting with water

Answer 10

Floats, fizzes, popping, jumping

Question 11

Potassium and water

Answer 11

Burning with a pink flame, moving around quickly, producing sparks

Question 12

Why do metals in group one (alkaline metals) react so aggressively with water and what is the trend going down through the group?

Answer 12

They only have one electron to lose, and as they go down the group the electrostatic attraction weakens because the atoms have more shelves - more aggressive reaction occurs.

Question 13

When a metal reacts with oxygen what does it form? What about chlorine?

Answer 13

With oxygen - a metal oxide, e.g Lithium oxide
With chlorine - a metal chloride, e.g Lithium chloride.

Question 14

List properties of TRANSITION metals

Answer 14

Harder than group one but less reactive too,
Good conductors of heat and electricity,
High density,
Produce coloured products,
Have difference in charges
Malleable and ductile
Can be catalysts

Question 15

Useful acronym referring to redox reactions

Answer 15

O - oxidation
I - is
L - loss
R - reduction
I - is
G - gain
of electrons

Question 16

What does an ionic equation show

Answer 16

Only the atoms that are affected, this can then be made into half equations (redox) that show reduction or oxidation in relation to electrons

Question 17

How to perform an oxidation equation (the atom that loses electrons)

Answer 17

First - make an ionic equation by removing the spectator atoms, then pick the atom that loses electrons to make an ion - Ca -> Ca^2+ + 2e^-

Question 18

Reactivity series in order with most reactive at the top

Answer 18

Please - Potassium
Stop - Sodium
Liking - Lithium
Cats - Calcium
My - Magnesium
Cool - Carbon
Zebra - Zinc
Has - Hydrogen
Copper