Chem paper 1

Question 1

Who created the Second Model of atoms and describe its shape

Answer 1

JJ Thompson created the plum pudding model in which it had a positive charge with small electrons scattered around it

Question 2

Which scientist discovered that the nucleus was small and positively charged

Answer 2

Ernest Rutherford

Question 3

How did Ernest Rutherford find out that protons were small

Answer 3

He shot Alpha particles at a small gold leaf in which most passed through but the ones shot in the middle were reflected showing that the nucleus did not cover the entire atom

Question 4

Which scientist discovered that electrons existed in shells

Answer 4

Neil Bohr

Question 5

Which scientist discovered that the nucleus of an atom had to contain neutrons alongside protons

Answer 5

James Chadwick

Question 6

What charge do each subatomic particle contain

Answer 6

-For protons there is a 1 positive charge
-For electrons there is a 1 negative charge
-For neutrons there is no charge that it emitts

Question 7

Explain the first and second Step in development of the periodic table

Answer 7

At the start Elements were ordered according to there atomic weight even though some were grouped together to having
Demetri Mendeleev organised the periodic table based on similar properties in which he left gaps in which would later be discovered

Question 8

What are the order of which shells can appear

Answer 8

First shell is two second is 8 third is 8 and fourth is 2 before repeating

Question 9

Do metals lose or gain electrons in order to gain a full outer shell

Answer 9

They lose Electrons

Question 10

Why are some Elements more reactive then others

Answer 10

Some elements are more reactive then others due to the electromagnetic forces of attraction being less

Question 11

True or False and if so why :
The Noble gasses are very unreactive

Answer 11

True
This is due to them already having a full outer shell

Question 12

How does Metallic Bonding occur

Answer 12

The metal atoms form a lattice (Grid) of ions surrounded by a sea of delocalised electrons

Question 13

How are ionic bonded structures Arranged

Answer 13

They are arranged in a lattice of repeating units of positive and negative ions which form crystals

Question 14

Give characteristics given to ionic structures

Answer 14

High boiling point and melting points

Question 15

Give characteristics given to metallic bonded structures

Answer 15

They are good conductors of electricity and heat

Question 16

Why are Metallic bonded structures Good at conducting heat and electricity

Answer 16

This is due to the electrons being free to move

Question 17

Why do ionic bonded structures have high melting and boiling points

Answer 17

This is due to strong ionic bonds because the ions have strong electromagnetic forces between them

Question 18

What are Fullerenes and what are they used for

Answer 18

They are 3d Giant covalent structures and are used for electronics and medical purposes

Question 19

What is the name given to one layer of graphite

Answer 19

Graphene

Question 20

What are Alloys

Answer 20

Alloys are a mixture of metals

Question 21

Why are metal Alloys on average harder then pure metals

Answer 21

This is due to the different sized atoms disrupting the lattice so that they cannot slide over each other so easily

Question 22

How do we calculate relative formula mass

Answer 22

We add the individual Relative atomic masses of the other elements

Question 23

What are the two ways in which you can calculate moles

Answer 23

mass(grams) Mass(Grams)
———————– OR ————————-
Relative Atomic Relative Formula
Mass Mass

Question 24

How do we calculate Moles of gas to volume

Answer 24

From Moles of gas to volume we times by 24
From volume to gas we divide by 24

Question 25

What Type of reaction is given to a chemical reaction that increases the temperature of the reaction

Answer 25

Exothermic Reaction

Question 26

What Type of reaction is given to a chemical reaction that Decreases the temperature of the reaction

Answer 26

Endothermic Reaction

Question 27

Explain the steps of to figure out if a reaction is Exothermic or Endothermic

Answer 27

-We React an acid with and Alkali and measure the maximum temperature reached
-Repeat with increasing volumes of alkali.
-The maximum temperature will eventually decrease as the alkali is in excess
-Where the two meet