1. Atomic structure & The periodic table (atoms, elements, mixtures, separating techniques)

Question 1

What is an atom?

Answer 1

• the smallest part of an element that can exist
• they make up everything

Question 2

What is an element?

Answer 2

A substance made from only one type of atom

Question 3

What is the mass of the proton, neutron and electron?

Answer 3

proton: 1
neutron: 1
electron: 1/2000 (negligable)

Question 4

What are the charges of the subatomic particles?

Answer 4

proton: +1
neutron: 0
electron: -1

Question 5

Where is most of the atom’s mass contained?

Answer 5

in the nucleus

Question 6

How many electrons can be in each shell?

Answer 6

1st: 2 electrons
2nd: 8 electrons
3rd: 8 electrons

Question 7

What is the mass number of an element?

Answer 7

the sum of protons and neutrons in an atom

Question 8

What is the atomic number?

Answer 8

the number of protons an element contains

Question 9

What is the overall charge of an atom?

Answer 9

neutral - because it has the same number of protons and electrons

Question 10

What does the group number of an element tell you?

Answer 10

the number of electrons it has on its outer-most shell

Question 11

What does the period tell you about the element?

Answer 11

The number of shells it has

Question 12

What is an isotope?

Answer 12

• a different version of the same element
• with the same number of protons but different number of neutrons

Question 13

what is the relative atomic mass of an element?

Answer 13

An average value that takes account of the abundance of the isotope of the element

Question 14

What is a compound?

Answer 14

two or more elements that are chemically combined

Question 15

What is a mixture?

Answer 15

2 or more elements or compounds that are not chemically combined

Question 16

Why and how can mixtures be separated?

Answer 16

• they are not chemically combined
• so can be separated using physical processes

Question 17

What is a solvent?

Answer 17

the liquid that the solute disolves in to form a solution

Question 18

What is a solute?

Answer 18

the minor component in a solution, dissolved in the solvent

Question 19

What is filtration?

Answer 19

A process that separates an insoluble solid from a solvent

Question 20

What are the steps for filtration?

Answer 20

1. Set up an apparatus in the correct manner. A conical flask with a funnel containing filter paper, and in a seperate breaker, the insoluble solid with the liquid
2. Pour the solution through the funnel
3. The filter paper will have the residue remaining in it, whilst the filtrate is collected in the conical flask

Question 21

What is crystillisation?

Answer 21

A process where you separate a soluble solid from a liquid

Question 22

What are the steps for crystillisation?

Answer 22

1. The mixture is first placed in an evapourating basin with a bunsen burner placed underneath
2. The heat from the bunsen burner will cause the liquid to evaporate whilst solid crystals of the solute form and are left behind

Question 23

What is simple distillation?

Answer 23

A process that separates the liquid from the soluble solid

Question 24

What are the steps for simple distillation?

Answer 24

1. First set up apparatus in the correct manner. The flask should be connected with a condenser and a conical flask with a bung having a thermometer placed in and a bunsen burner beneath.
2. The heat from the bunsen burner will cause the liquid to evaporate
3. The vapour of the liquid will travel through a condenser to be condensed and turned into a liquid to be collected
4. The residue is then left in the conical flask with the distillate now in the flask

Question 25

What is fractional distillation?

Answer 25

A process separating 2 or more liquids with different boiling points

Question 26

What are the steps for fractional distillation?

Answer 26

1. Place the mixture of liquids into the flask with the fractional column above with glass rods
2. Heat up the solution using a bunsen burner
3. The liquid with the lowest boiling point will evapourate first and will be collected

Question 27

What is chromotography?

Answer 27

A technique used to separate the dyes that make up ink

Question 28

What are the steps for chromotography?

Answer 28

1. First draw a pencil line onto filter paper and place a spot of ink in the middle of the line
2. Place the filter paper into a beaker with a solvent. The solvent should be just below the line and the spot drawn
3. Place a lid on top of the container to stop the solvent evapourating
4. The solvent then seeps up the paper, carrying the different dyes up the paper

Question 29

Why is the line drawn in pencil and not pen in chromotography?

Answer 29

Because pencil marks are insoluble, and pen has dye so would become part of the experiment

Question 30

Why does the solvent have to be below the line? (chromotography)

Answer 30

So the ink spot doesn’t dissolve in the solvent

Question 31

What is the solvent front?

Answer 31

the point the solvent has reached as it moves up the paper

Question 32

What is the end result of a chromatography experiment called?

Answer 32

A chromatogram