Atomic Structure Chemistry

Question 1

what are all substances made up of?

Answer 1

Atoms

Question 2

what do chemical reactions involve?

Answer 2

the formation of one or more new substances, and often a detectable energy change

Question 3

what is a mixture?

Answer 3

a combination of two or more elements or compounds not chemically combined together

Question 4

how can mixtures be separated?

Answer 4

by physical processes, such as:
-filtration
-crystalisation
- simple distillation
- fractional distillation
- chromatography

Question 5

how did the plum pudding model change?

Answer 5

• the results from the alpha particle scattering experiment led to the conclusion that the mass of an atom was concentrated at the nucleus, which was charged
• Niels Bohr adapted the nuclear model by suggesting that electrons orbit the nucleus at specific distances (theoretical calculations agreed with experimental observations)

Question 6

what are the charges of the particles in atoms?

Answer 6

• proton +1
• neutron 0
• electron -1

Question 7

what is the relative mass of each particle in an atom?

Answer 7

• proton 1
• neutron 1
• electron very small

Question 8

what is the mass number?

Answer 8

the number of protons and neutrons

Question 9

what is an isotope?

Answer 9

when atoms of the same element have a different number of neutrons

Question 10

how are elements in the periodic table arranged?

Answer 10

in order of increasing atomic (proton) number

Question 11

what is a metal?

Answer 11

an element that reacts to form positive ions

Question 12

what is a non-metal?

Answer 12

elements that do not form positive ions

Question 13

what are the properties of group 0 elements nobale gases

Answer 13

• unreactive
• do not easily form molecules as they have stable electron arrangements
• eight electrons in the outer shell (except hydrogen)
• boiling point increases with relative atomic mass but still remains low

Question 14

What is a molecule

Answer 14

a substance made of two or more atoms joined together by a bond

Question 15

What is a compund

Answer 15

a substance made of at least two different types of atom chemically bonded together

Question 16

What is a mixture

Answer 16

two or more substances that are mixed together but are not joined by bonds

Question 17

Define nucleus

Answer 17

the centre part of an atom that contains the protons and neutrons

Question 18

What was Rutherford’s experiment

Answer 18

the experiment that proved the nucleus must be positively charged (as alpha particles were scattered/deflected by a piece of gold foil)

Question 19

What is the plum pudding model

Answer 19

a model of the atom that proposed the nucleus was a ball of positive charge with negative electrons embedded in it (we now know this is incorrect)

Question 20

What is chromatography

Answer 20

a technique commonly used to separate a mixture of dyes in ink

Question 21

What is crystallisation

Answer 21

a technique used to separate a soluble solid (or salt) from a solution

Question 22

Define filtration

Answer 22

a technique used to separate an insoluble substance from a solvent (one that does not dissolve)

Question 23

What is the periodic table

Answer 23

the way in which the elements are organized and classified. Called this because of the regularlly repeating patterns.

Question 24

Who was John Dalton

Answer 24

the scientist who proposed one of the first periodic tables, he organized the elements in order of atomic weight

Question 25

Who was John Newlands

Answer 25

the scientist who built on the ideas of Dalton and arranged elements into sets of eight (as he found that each eighth element had similar properties)

Question 26

Who was Dmitri Mendeleev

Answer 26

the Russian chemist who proposed the periodic table we use today- he left gaps for undiscovered elements.. his table was accepted by scientific community

Question 27

We’re are metals on the table

Answer 27

the elements found to the left of the periodic table, they are electrical conductors

Question 28

We’re are alkali metals found

Answer 28

group 1 of the periodic table.
-Melting points and boiling increase going down the group
-react with water to produce hydrogen and metal hydroxide
-reactivity increases down the

Question 29

We’re are the halogens found

Answer 29

group 7 of the periodic table.
-reactivity decreases as you go down the group
-all form negative ions in their ionic compounds
-form covalent bonds with other non metals

Question 30

We’re are transition metals found

Answer 30

the middle block of metals in the periodic table, containing elements such as: copper, gold and iron. Compared to alkali metals much higher melting points and densities. Stronger and harder but much less reactive
- they don’t react vigorously with water
-form ions with different charges
- elements and transition compounds form important industrial

Question 31

reaction of sodium with water

Answer 31

melts to form a ball, fizzes rapidly and may form an orange flame

Question 32

What are two products formed when an alkali metal reacts with water

Answer 32

metal hydroxide + hydrogen

Question 33

What is displacement reaction

Answer 33

a reaction in which a more reactive halogen takes the place of a less reactive halogen