C1: Atomic Structure and the Periodic Table

Question 1

What is an atom?

Answer 1

the smallest part of an element that can exist on its own

Question 2

What is an element?

Answer 2

a substance that only contains one sort of atom

Question 3

What is a compound?

Answer 3

a substance that contains atoms of two or more elements, which are chemically combined in fixed proportions

Question 4

What do scientists use chemical formulae to show?

Answer 4

the different elements in a compound, how many atoms of each element one molecule of the compound contains

Question 5

What is the conservation of mass?

Answer 5

the total mass of the products of a chemical reaction is always equal to the total mass of the reactants (no atoms are lost or made)

Question 6

What is a mixture?

Answer 6

a substance that consists of tow or more elements. which are not chemically combined

Question 7

What is filtration?

Answer 7

separation of liquids from insoluble solids

Question 8

What is crystallisation?

Answer 8

used to obtain a soluble solid from a solution of a solution

Question 9

What is simple distillation?

Answer 9

used to obtain a solvent from a solution

Question 10

What is fractional distillation?

Answer 10

used to separate mixtures in which the components have different boiling points

Question 11

What is chromotography?

Answer 11

used to separate the different soluble, often coloured, components of a mixture

Question 12

In early models, what were atoms thought to be?

Answer 12

tiny spheres that could not be divided into simpler particles

Question 13

When were electrons discovered and by who?

Answer 13

1898 by Thomson (plum pudding model)

Question 14

What did the plum pudding model consist of?

Answer 14

atoms containing tiny, negative electrons surrounded by a sea of positive charge

Question 15

What experiment did Geiger and Marsden carry out? What results did they obtain?

Answer 15

they bombarded a thin sheet of gold with alpha particles, although most of the positively charged alpha particles passed straight through the atoms, a tiny number were reflected back towards the source

Question 16

What did Rutherford conclude from this?

Answer 16

the positive charge in an atom must be concentrated in a very small area (the nucleus)

Question 17

What did Bohr deduce?

Answer 17

electrons must orbit the nucleus at specific distances or they would spiral inwards

Question 18

Who provided evidence of neutrons in the nucleus?

Answer 18

James Chadwick

Question 19

What is the typical atomic radius of an atom?

Answer 19

around 0.1nm or 1x10^-10m

Question 20

Why does an atom have an overall neutral charge?

Answer 20

it has an equal number of protons and electrons

Question 21

What is an isotope?

Answer 21

atoms of the same element that have the same atomic number but a different mass number

Question 22

What is an ion?

Answer 22

atoms that have gained or lost electrons and now have an overall charge

Question 23

What ions do metals form?

Answer 23

positive (lose electrons)

Question 24

What ions do non-metals form?

Answer 24

negative (gain electrons)

Question 25

What is the electronic configuration of an atom?

Answer 25

shows how the electrons are arranged around the nucleus in shells

Question 26

In 1864, who tried to put together a periodic table and how many elements were known?

Answer 26

John Newlands, 63 elements

Question 27

How did Newlands arrange the periodic table?

Answer 27

by atomic weight

Question 28

In 1869, what did Dmitri Mendeleev do differently to Newlands?

Answer 28

left gaps for undiscovered elements and reordered some

Question 29

When the subatomic particles were discovered, how was it revealed that Mendeleev had ordered the elements?

Answer 29

by atomic number (number of protons)

Question 30

What are the Group 0 elements known as?

Answer 30

noble gases

Question 31

How do the boiling points change down Group 0?

Answer 31

they increase

Question 32

What are most Group 1 metals known as?

Answer 32

alkali metals

Question 33

How do the melting and boiling points of Group 1 metals differ?

Answer 33

they decrease down the group

Question 34

How does reactivity change down Group 1?

Answer 34

they become more reactive, because the outer electron gets further away from the influence of the nucleus so is more easily lost

Question 35

What are the Group 7 elements known as?

Answer 35

halogens

Question 36

How does reactivity change down the group (7)?

Answer 36

it decreases, because the outer shell of electrons gets further away from the nucleus so it is less easy to gain an electron

Question 37

Where are transition metals found?

Answer 37

between Groups 2 and 3

Question 37

What is produced when halogens react with metals?

Answer 37

ionic salts

Question 38

What can they be used for?

Answer 38

catalysts to speed up reactions