Topic 1 - Atomic Structure

Question 1

All substances are made from?

Answer 1

Atoms.

Question 2

Substances made from only one type of atom are called?

Answer 2

Elements.

Question 3

The periodic table is arranged in?

Answer 3

Groups of elements with shared properties.

Question 4

Give an example of a group in the periodic table.

Answer 4

Group 1, the Alkali Metals.

Question 5

What is the name given to structures containing more than one element bonded together?

Answer 5

A compound.

Question 6

Finish the sentence about atomic structure - Every atom is made up of a _______ and _________ orbiting it in ________.

Answer 6

Nucleus, Electrons, Shells.

Question 7

What do we mean by a “balanced” equation?

Answer 7

An equation with an equal amount of each element on each side.

Question 8

Balance the equation for water. This equation is imbalanced -> H2 + O2 ————> H2O

Answer 8

2H2 + O2 ——> 2H2O

Question 9

Give the law of conservation of mass.

Answer 9

The mass of products formed in a reaction is equal to mass of reactants.

Question 10

What is a difference between a compound and a mixture?

Answer 10

Compounds have a fixed composition of elements that are bonded together whereas mixtures have no fixed composition and can be made up of many elements at once.

Question 11

List four ways of separating compounds in a mixture.

Answer 11

Crystallisation, Filtration, Distillation, Chromatography.

Question 12

What does filtration do?

Answer 12

Separates compounds that are soluble in the solvent from ones which are insoluble in the solvent. For example separating water from sand using filtration paper.

Question 13

What does Crystallisation do?

Answer 13

Separates elements that can be evaporated from one’s that cannot by evaporation and allow the solid element to cool and crystallise, forming pure crystals of the element.

Question 14

What is the difference between distillation and crystallisation?

Answer 14

Crystallisation doesn’t collect the evaporative element whereas distillation cools and condenses the evaporative element into a liquid again to be collected, making the new liquid pure.

Question 15

Why is paper chromatography useful for separating elements?

Answer 15

Some elements will dissolve better than others in the solvent, the solubility of the element being determined by how far up the chromatogram the elements go.

Question 16

Who were the first peoples to have ideas about the atom?

Answer 16

The Greeks.

Question 17

What did the Greeks think about the atom?

Answer 17

That it was a small, undivided ball of metal.

Question 18

What was Dalton’s breakthrough about the structure of the atom?

Answer 18

Each atom were hard, tiny spheres and that each chemical element had their own type of atom.

Question 19

Who discovered the electron?

Answer 19

J.J Thompson

Question 20

How did J.J Thompson discover this?

Answer 20

By applying high voltages to gases at high temperatures.

Question 21

What did J.J Thompson find out about electrons?

Answer 21

That they were negatively charged and were smaller than atoms and made up atoms, discovering that there were smaller things than the atom.

Question 22

What was J.J Thompson’s new Plum Pudding model like?

Answer 22

He proposed that electrons floated in a sea of positive charged randomly like plums in a pudding

Question 23

Who made the breakthrough about alpha particles and the nucleus?

Answer 23

Geiger and Marsden.

Question 24

What did Geiger and Marsden discover about the nucleus?

Answer 24

That it had to be a highly dense concentration of positive charge as, in their gold foil experiment, most positively charged particles went straight through the atom, but ones which hit the nucleus fired straight back, this happened very rarely and they determined most of the atom was empty space.

Question 25

What was proposed after Geiger and Marsden’s breakthrough?

Answer 25

That the nucleus contained positively charged protons and that negatively charged electrons orbited around the nucleus in shells.

Question 26

What did James Chadwick add to the atomic model?

Answer 26

James Chadwick observed a discrepancy between predicted and real mass of the nucleus and determined that neutrally charge neutrons were present in the nucleus alongside the protons.

Question 27

What sub-atomic particles are contained in the nucleus?

Answer 27

Protons and Neutrons.

Question 28

What sub-atomic particle type orbits around the nucleus?

Answer 28

Electrons.

Question 29

What is the relative mass and charge of a proton?

Answer 29

Protons have a relative mass of 1 and a relative charge of +1.

Question 30

What is the relative mass and charge of a neutron?

Answer 30

A neutron has a relative mass of 1 and a relative charge of 0.

Question 31

What is the relative mass and charge of an electron?

Answer 31

An electron has a relative mass of 1/2000 (nearly 0) and a relative charge of -1.

Question 32

What is the name given to the number of protons in an element?

Answer 32

Atomic Number.

Question 33

What is the name given to the total mass of protons and neutrons in an element?

Answer 33

Mass Number.

Question 34

What is an ion?

Answer 34

An atom which has lost or gained electrons compared with its original form. In other words, it is a charged atom.

Question 35

Atoms of the same element but different numbers of neutrons are called?

Answer 35

Isotopes.

Question 36

Electrons orbit the nucleus in?

Answer 36

Shells or energy levels.

Question 37

How many electrons fit inside the first shell?

Answer 37

2

Question 38

How many electrons fit inside the second and third shells?

Answer 38

8

Question 39

What is the arrangement of electrons in Oxygen? (Atomic number 8)

Answer 39

2,6

Question 40

What is the arrangement of electrons in Aluminium? (Atomic number 13)

Answer 40

2,8,3

Question 41

What is the arrangement of electrons in Calcium? Atomic number 20)

Answer 41

2,8,8,2

Question 42

Elements in Group 0 (8) of the periodic table are called?

Answer 42

Noble gases.

Question 43

What is the most unreactive group of elements?

Answer 43

Noble gases/group 0.

Question 44

When is fractional distillation used?

Answer 44

When separating more than two types of liquids from a homogeneous mixture. E.g. different hydrocarbons from crude oil.

Question 45

What is the method for paper chromatography?

Answer 45

Place a sheet of paper in a beaker filled with a shallow layer of your solvent.

Ensure the level of solvent is below the pencil line.

Place a lid on the beaker and leave the solvent to travel up the paper, carrying the different compounds of the mixture to different levels of the chromatogram.

Question 46

How do you calculate Rf value?

Answer 46

Divide the distance travelled by the component by the distance travelled by the solvent.

• This is part of paper 2 but still useful.

Question 47

Why can we be sure that there are no missing elements in the first 10 elements?

Answer 47

We have named, identified and characterised all of the 10 elements and since protons cannot be split, there cannot be unknown elements within the periodic table.

Question 48

Why do group 1 elements increase in reactivity as we go down the periodic table?

Answer 48

Because, since they have greater atomic numbers, their outer shells are further away from the nucleus and since they lose electrons in group 1, they have less of a strong bond with the nucleus and thus it can lose its outer electron more quickly.

Question 49

Why do group 7 elements decrease in reactivity as we go down the periodic table?

Answer 49

Group 7 elements gain electrons, since their outer shells are closer to the nucleus if they have a lower atomic number and are thus higher up the perioidic table, they can attract an electron more easily if they have a low atomic number. Thus they are more reactive.