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Question 1

How are elements ordered in the periodic table?

Answer 1

In order of their atomic weights

Question 2

How are elements arranged in groups and periods in the periodic table?

Answer 2

Elements with similar properties were put in the same group and they are ordered in order of their atomic weights

Question 3

Why was the periodic table a breakthrough in how to order elements?

Answer 3

Because before this there was no correct way of ordering elements and no way to properly understand chemical elements.

Question 4

What is a group in the periodic table?

Answer 4

Vertical columns which contain elements with similar properties.

Question 5

What is a period in the periodic table?

Answer 5

The horizontal rows in a periodic table.

Question 6

How does electronic structure in group 1,2 and 3 link to the periodic table?

Answer 6

Because group 1,2 and 3 on the periodic table have to lose electrons to attain the electronic structure of the noble gases.

Question 7

Are noble gases reactive or unreactive?

Answer 7

Unreactive

Question 8

Compare the electronic structure of a metal and non metal

Answer 8

Metals conduct electricity but non metals are usually electrical insulators. Exceptions are some forms of carbon. In general, metals also have much higher melting and boiling. Metals are ductile and malleable, whereas non metals solids are brittle.

Question 9

Why are noble gases unreactive?

Answer 9

They are monatomic (single-atom) gases. So they have no tendancy to react and modify their electronic structures by forming molecules.

Question 10

Explain the noble gases trends in their boiling points

Answer 10

The boiling points get higher going down group 0. Helium at the top boils at -269°C whereas radon,at the bottom boils at -62°C.

Question 11

Name the first three elements in group 1

Answer 11

Lithium (Li), sodium (Na) and potassium (k)

Question 12

Do they group 1 metals have low or high densities?

Answer 12

Low densities

Question 13

Write a word equation of how a group 1 metal reacts with water

Answer 13

Sodium + water – sodium hydroxide + hydrogen

Question 14

Explain why the first three group 1 elements float on water

Answer 14

The water reacts with the metal to form hydrogen gas. Potassium reacts so vigorously with water that the hydrogen produced ignites. It burns with a lilac flame, coloured by the potassium ions formed in the reaction.

Question 15

How can you show that hydrogens and metal hydroxides are made when group 1 metals react with water?

Answer 15

They are called alkali metals because they also produce a metal hydroxide when reacting with water. The hydroxides of alkali metals are all soluble in water. This solution is colourless with a high pH.

Question 16

What safety precautions have to be taken when dealing with group 1 metals?

Answer 16

They are to be stored in oil which stops them reacting with oxygen in the air.

Question 17

How do group 1 metals form ions with a +1 charge when they react with non-metals? (Optional question, very long answer, will probably help in the exam though)

Answer 17

They react vigorously with non-metals such as chlorine gas, which produce metal chlorides, which are white solids. The metal chlorides all dissolve readily in water to from colourless solutions. Reactions get more vigorous as you go down the group. Because it becomes easier to lose the single electrons in the outer shell to form ions with a +1 charge. They react in a similar way with fluorine, bromine and iodine. The solutions formed are all colourless.

Question 18

Name the first 4 elements in group 7

Answer 18

Fluorine, chlorine, bromine and iodine

Question 19

Describe the main properties of halogens

Answer 19

They have low melting points and boiling points. Their melting and boiling points increase going down the group.

They are poor conductors of heat and electricity.

Question 20

Explain why elements in group 7 react similarly

Answer 20

Because they all have 7 electrons in their outermost shell and their electronic structure determines the way they react with other elements.

Question 21

What is the trend in reactivity in group 1?

Answer 21

Get more reactive going down the group

Question 22

What is the trend in reactivity in group 7?

Answer 22

The elements get less reactive going down the group

Question 23

How does electronic structure affect the trend of group 1 elements?

Answer 23

Because the atoms get larger so the single electron in the outermost shell (highest energy level) is attracted less strongly to the positive nucleus. The electrostatic attraction with the nucleus gets weaker because the distance between the outer electron and the nucleus increases.

Question 24

How does the electronic structure affect the trend in reactivity in group 7?

Answer 24

When group 7 elements react their atoms gain an electron in their outermost shell. Going down the group the outermost shell’s electrons get further away from the attractive force of the nucleus, so it is harder to attract and gain an extra incoming electron.

Question 25

What does the group number of the periodic table tell you about an element?

Answer 25

The group number in the periodic table tells you the number of electrons in the outermost shell of an atom.

Question 26

What model for ordering elements was made in 1808?

Answer 26

In 1808 John Dalton arranged the elements in order of their atomic weight.

Question 27

What significant model was made in 1864 for ordering elements?

Answer 27

John Newlands made a ‘law of octaves’ table.

Question 28

What was the problem with John Newlands ‘law of octaves’ table?

Answer 28

He assumed all elements had been found. Didn’t take into account that chemists were still forming new ones. So he filled in his octaves even though some of the elements were not similar at all.

Question 29

What elements did John Newlands ‘law of octaves’ table work up to?

Answer 29

Calcium

Question 30

What happened in 1869 with ordering elements?

Answer 30

Russian chemist, Dmitri Mendeleev cracked the problem, when around 50 elements had been discovered.

Question 31

What did Mendeleev do with the elements?

Answer 31

He arranged them in a table. He placed them in the order of their atomic weights.

Question 32

What was Mendeleev’s last step?

Answer 32

He arranged the elements so that a periodic pattern in their properties could be seen.

Question 33

What was the only problem with Mendeleev’s breakthrough?

Answer 33

Not all elements fell in with his pattern, for example argon. It was a mystery for decades.

Question 34

When did scientists start to learn more about the structure of an atom?

Answer 34

Not until the start of the 20th century.

Question 35

How does electronic structure in group 5,6 and 7 link to the periodic table?

Answer 35

Group 5,6 and 7 gain electrons to form negative ions to attain the electronic structure of noble gases.