Chapter C1 - Atomic Structure

Question 1

Describe how to carry out paper chromatography {5 marks}

Answer 1

• Draw a line near the bottom of a sheet of filter paper, using a pencil
• Add a spot of the ink to the line and place the sheet in a beaker of solvent, e.g water
• Place a lid on top of the container to prevent evaporation
• Each dye moves at different rates
• Insoluble dyes won’t move
• When the solvent has nearly reached the top, leave it to dry

Question 2

what is the top number and what does it tell you? {2 marks}

Answer 2

mass number

total no. protons and neutrons

Question 3

Describe the process of filtration {3 marks}

Answer 3

• Seperates insoluble solids from liquids
• Filter paper folded into cone shape
• Solid left in the filter paper, seperated

Question 4

how many protons and neutrons does element contain? {2 marks}

Answer 4

Protons - 2

Neutrons - 2

Question 5

Define isotopes? {2 marks}

Answer 5

• Different forms of the same element
• Same no. protons, different no. neutrons

Question 6

The chemical equation for a reaction of sodium is shown below:

2Na + Cl2 = 2NaCl

Describe this reaction of sodium in terms of the names of the substances and the numbers of the atoms involved {3 marks}

Answer 6

• two sodium atoms react
• two bonded chlorine atoms
  (react) two sodium ions and two chloride ions (are produced)

Question 7

roughly how many different elements are there? {1 mark}

Answer 7

100

Question 8

how many protons and neutrons does element contain? {2 marks}

Answer 8

protons - 11

neutrons - 12

Question 9

what is the bottom number and what does it tell you {2 marks}

Answer 9

atomic number

total no. protons

Question 10

Name the relative charges of Protons, Neutrons and Electrons? {3 marks}

Answer 10

Protons : +1

Neutrons : 0

Electrons : -1

Question 11

Describe the process of crystallisation {6 marks}

Answer 11

• Used to seperate soluble solids from solutions
• Pour the solution into an evaporating dish and gently heat
• Some solvent will evaporate
• At the point of crystallisation, remove the dish from the heat and leave it to cool
• Salt forms crystals as it becomes insoluble
• Filter crystals out of the solution, leave them to dry in a drying oven.

Question 12

Describe the process of evaporation {4 marks}

Answer 12

• Seperates soluble solids from solutions
• Pour the solution into evaporating dish
• Slowly heat the solution
• Solvent will evaporate and crystals will start to form
• Keep heating until you are left with dry crystals

Question 13

What makes mixtures easy to seperate {1 mark}

Answer 13

• no chemical bond between the different parts of the mixture