Topic 2 - The Periodic Table.

Question 1

Dalton arranged the elements in what order?

Answer 1

Atomic Weights/Masses.

Question 2

John Newlands also arranged elements in weight order but noticed one key similarity between elements, what was this?

Answer 2

Each 8th element seemed similar.

Question 3

John Newlands drew up a table in an order called? What was one key problem he knew he was facing with this?

Answer 3

The law of octaves, he knew that not all of the elements had been discovered so he couldn’t arrange all of them in the correct order.

Question 4

Who solved the problem that John Newlands was facing?

Answer 4

Dimitri Mendeleev.

Question 5

Mendeleev arranged all of the 50 known elements into periods based on what?

Answer 5

Similar properties that the elements had with one another.

Question 6

What did Mendeleev do in the late 1800s that scientists found to prove his table right?

Answer 6

Mendeleev added gaps into the table where elements hadn’t been found yet, predicting their properties with great accuracy.

Question 7

There were discrepancies with the masses of certain elements in the table, which couldn’t be explained until the 20th century, what discovery answered this problem?

Answer 7

The discovery of neutrons in 1932 explains the differences in mass due to different numbers of neutrons changing mass readings.

Question 8

Why was John Newlands’ Law of Octaves table not accepted?

Answer 8

He filled in certain octaves whilst scientists were still discovering elements, making some of his groups not similar at all and the pattern broke down.

Question 9

The non-metals are found in the ___-______ of the periodic table, in groups 5-8, where elements _____ electrons. Finish the sentence with the right words.

Answer 9

Top right, gain.

Question 10

Explain the electronic structure of the noble gases.

Answer 10

They have 8 electrons on their outer shell making them stable and unreactive with other elements.

Question 11

Noble gases are usually ___________, so they have very low ________ _______ and are almost always in ___ form. Finish the sentence with the right words.

Answer 11

Monoatomic, boiling point, gas.

Question 12

The first group of metals (group 1) is called the?

Answer 12

Alkali Metals.

Question 13

Finish the sentence with the right words - Alkali Metals are all very ________ and they have a very low _______ compared with other elements, they also have low ______ ________ .

Answer 13

Reactive, density, melting/boiling point.

Question 14

What happens when an alkali metal reacts with water?

Answer 14

The metal fizzes and dissolves due to the intense reaction taking place, creating Hydrogen gas.

Question 15

Finish the sentence about alkali metals. Alkali metals also react _________ with certain non-metals like when Sodium reacts with ________ to make Sodium _________.

Answer 15

Vigorously, Chlorine, Chloride.

Question 16

Elements in group 7 are called what?

Answer 16

The halogens.

Question 17

Name three properties of the Halogens.

Answer 17

They have a very low boiling/melting point.
They are poor conductors of heat and electricity.
They exist as diatomic molecules bonded by a covalent bond.

Question 18

How many electrons do Halogens have on their outer shell and thus how many electrons do they have to gain to complete their outer shell?

Answer 18

Halogens have 7 electrons on their outer shell and have to gain 1 to complete it.

Question 19

Name a rule that describes the order of reactivity in Halogens.

Answer 19

A more reactive halogen will displace a less react halogen.

Question 20

Finish the displacement reaction between Chlorine and Potassium Bromide —> Cl2 + KBr ——> _____ + _____

Answer 20

Cl2 + KBr ——> KCl + Br2
The Chlorine has displaced the Bromine bonded with the Potassium as it is more reactive.

Question 21

As you go down group 1, elements become more reactive, why?

Answer 21

Because the further down the table, the higher the atomic number of the element, therefore it has more shells and the outer shell is further away than elements further up the group, so they can lose the electron easier as their is a smaller force pulling them together.

Question 22

Reactivity goes down as you go down group 7, why?

Answer 22

The elements at the top of group 7 have their outer shell closer to the nucleus and therefore have a greater force of attraction to gain an electron, whereas elements that have their outer shell further away in group 7 have a smaller force of attraction to gain an electron.

Question 23

The transition metals are situated between which two groups?

Answer 23

Groups 2 and 3.

Question 24

List some properties of the transition metals.

Answer 24

They are good conductors of electricity and thermal energy.
They are hard and strong.
They have high densities.
They have extremely high melting points.

Question 25

The transition metals are much less reactive than the ______ ______. What two words finish the sentence?

Answer 25

Alkali Metals.

Question 26

Give some examples of coloured compounds formed by the transition metals.

Answer 26

Copper (II) Sulfate is blue due to its Cu 2+ions.
Nickel (II) Carbonate is pale green due to the Ni 2+ ions.
Chromium (III) oxide dark green due to its Cr 3+ ions.
Manganese (II) Chloride is pale pink due to its Mn 2+ ions.