the periodic table-c2

Question 1

What was John Daltons suggestion for the periodic table?

Answer 1

He arranged the elements in order of their atomic weights.

Question 2

What did John Newlands do?

Answer 2

In 1864 John Newlands built on Dalton’s ideas. Newlands also arranged the known elements in order of mass but noticed that the properties of every eighth element seemed similar.
He produced a table showing his ‘law of octaves’. However he assumed that all the elements had been found. He did not take into account that chemists were still discovering new ones. So he filled in his octaves, even though some of his elements were not similar at all. His table only worked up to known elements up to calcium. Other scientists ridiculed his ideas and refused to accept them.

Question 3

What did Mendeleev do?

Answer 3

In 1869, Dmitri Mendeleev cracked the problem. At this time around 50 elements had been identified. Mendeleev arranged all of these in a table. He placed them in order of atomic weights. Then he arranged them so that a periodic pattern in their properties could be seen.
He left gaps for elements that had not yet been discovered. Then he used his table to predict what their properties should be. A few years later, new elements were discovered with properties that closely matched Mendeleev’s predictions.

Question 4

More about Mendeleev and his scientific breakthrough(just read it lol)

Answer 4

However not all elements fir with Mendeleev’s pattern. One example is argon. Ordering them in atomic weights would result in argon(a noble gas) being in the same group as potassium(extremely reactive). So argon’s position had to be changed to maintain the periodic pattern. Mendeleev changed the order to keep elements with similar properties in the same group.
Then in the 20th century, scientists found out more about the atom, the discovery of isotopes confirmed Mendeleev was correct not to place elements in strict order of atomic masses but also take into account their properties. Isotopes of the same element have different atomic masses but also have the same chemical properties so occupy the same position on the periodic table.

Question 5

Facts about the periodic table and how its arranged(just make sure you understand)

Answer 5

The elements are placed in order of their atomic number in the periodic table. This arranges the elements so they line up in groups with similar properties.

Question 6

How many groups are there in the periodic table?

Answer 6

8

Question 7

Why do elements in the same group react the same way?

Answer 7

Because their atoms have the same number of electrons in the outer shell. The group number in a periodic table tells you the number of electrons in the outermost shell, e.g all the atoms in group 2 have 2 electrons in their outer shell.

Question 8

What are the difference between metals and non metals for their physical propeties?

Answer 8

Metals are strong, but malleable(bent into shapes). They are great at conducting heat and electricity. They have high boiling and melting points.
As non metals don’t have metallic bonding, they have different properties. They tend to be dull looking, more brittle, are not always solids are room temperature, do not conduct electricity and have a lower density.

Question 9

Why do elements react/

Answer 9

To form a full outer shell

Question 10

Why is it easier for metals to form positive ions?

Answer 10

Metals to the left of the periodic table don’t have many electrons to remove and metals towards the bottom of the periodic table have outer electrons that are a long way from the nucleus so feel a weaker attraction. Both of these effects mean that not much energy is needed to remove the electrons so it is easier for the elements to form positive ions with a full outer shell.

Question 11

Why is it harder for non metals to form positive ions?

Answer 11

For non metals, forming positive ions is much more difficult. This is because they are either to the right of the periodic table-where they have lots of electrons to remove to get a full outer shell or towards the top- where the outer electrons are close to the nucleus so feel a strong attraction. Its more easier for non metals to share or gain electrons to get a full outer shell.

Question 12

What are group 0 elements called?

Answer 12

The noble gases

Question 13

What elements are in group 0?

Answer 13

Helium, neon and argon and a few others

Question 14

Why are noble gases very stable?

Answer 14

They all have 8 electrons in the outer shell, apart from helium which has 2 but still gives it a complete shell. As their outer energy shell is stable they don’t need to react to gain or lose electrons. This means they are inert-don’t react a lot.

Question 15

some facts about group 0 (im v proud of you for revising, you got this :)

Answer 15

• they exist as monatomic gases- single atoms not bonded to each other
• all elements in group 0 are colourless gases at room temperature.
• as the noble gases are inert they are non flammable

Question 16

What is the trend in boiling point as you go down group 0?

Answer 16

The boiling points increase as you move down the group and their relative atomic mass increases too.

Question 17

Why does the boiling point increase as you go down group 0?

Answer 17

The increase in boiling point is due to an increase in the number of electrons in each atom leading to greater inter molecular forces between them which need to be overcome

Question 18

What are group 1 metals known as?

Answer 18

Alkali metals

Question 19

What are the elements in group 1?

Answer 19

lithium, sodium, potassium, rubidium, caesium and francium

Question 20

What are the propeties of group 1 metals?

Answer 20

Soft, low density, all have one electron in outer shell which makes them very reactive and gives them similar propeties.

Question 21

Why are group 1 metals so reactive?

Answer 21

They only need to lose one electron to get a stable electronic structure

Question 22

What happens to the reactivity of group 1 as you go down the group?

Answer 22

The reactivity increases-the outer electron is more easily lost as the attraction between the nucleus and electron decreases, because the electron is further away from the nucleus the further down the group you go.

Question 23

What happens to the melting and boiling points as you go down group 1?

Answer 23

Lower melting points and boiling points as you go down

and ofc the higher relative atomic mass goes up

Question 24

info about group 1 metals reacting

Answer 24

The group 1 elements don’t need much energy to lose their one outer electron to form a full outer shell, so they readily form 1+ ions.
It’s so easy for them to lose their outer electron that they only ever react to form ionic compounds. These compounds are usually white solids that dissolve in water to form colourless solutions.

Question 25

What happens when alkali metals react with water?

Answer 25

When group 1 metals are put in water, they react vigorously to produce hydrogen gas and metal hydroxides- salts that dissolve in water to produce alkaline solutions.
sodium+water=sodium hydroxide+hydrogen
2Na+2H2O=2NaOH+H2
the more reactive(lower down) an alkali metal is, the more violent the reaction
the amount of energy given out by the reaction increases down the group.

Question 26

What do alkali metals look like when you cut them?

Answer 26

They have a silvery, shiny surface when you first cut but this quickly goes dull as the metals react with oxygen in the air, this forms a layer of oxide on the shiny surface e.g sodium+oxygen= sodium oxide

Question 27

What happens when group 1 metals react with chlorine?

Answer 27

Group 1 metals react vigorously when heated in a chlorine gas to form white metal chloride salts.
sodium+chlorine=sodium chloride
2Na+Cl2=2NaCl
As you go down the group, reactivity increases so the reaction with chlorine gets more vigorous.

Question 28

more detail about each element in group 1 when it reacts with water

Answer 28

When you add lithium, sodium or potassium to water, the metal floats on the water, moving around and fizzing. The fizzing happens because the metal reacts with the water to form hydrogen gas. Potassium reacts so vigorously with water that the hydrogen produced ignites. It burns with a lilac flame.

Question 29

What are the differences in properties between group 1 metals and transition metals?

Answer 29

Group 1 metals are much more reactive than transition metals- they react more vigorously with water, oxygen or group 7 metals.
They are also much less dense, strong and hard than transition metals and have lower melting points.

Question 30

What are group 7 elements known as?

Answer 30

Halogens which are all non metals with coloured vapours. They all exist as molucoles which are pairs of atoms.

Question 31

What is Fluorine like?

Answer 31

Very reactive and poisonous yellow gas

Question 32

What is Chlorine like?

Answer 32

Fairly reactive and poisonous dense green gas

Question 33

What is bromine like?

Answer 33

Bromine is a dense, poisonous, red-brown volatile liquid

Question 34

What is iodine like?

Answer 34

Iodine is a dark grey crystalline solid or a purple vapour

Question 35

What happens to the reactivity of group 7 as you go down the group?

Answer 35

They become less reactive as you go down because it is harder to gain an extra electron, because the outer shell is further from the nucleus

Question 36

What happens to the melting and boiling points of group 7 as you go down the group?

Answer 36

As you go down, the melting and boiling points increase

and ofc as you go down higher relative atomic mass

Question 37

Why do all group 7 react in a similar way?

Answer 37

They all have 7 electrons in their outer shell

Question 38

How can halogens get a full outer shell?

Answer 38

Halogens can share atoms electrons through covalent bonding with other non metals to get a full outer shell.

Question 39

What do halogens form when they react with metals?

Answer 39

1- ions called halides

Question 40

When does a displacment reaction occur?

Answer 40

A displacement reaction can occur between a more reactive halogen and the salt of a less reactive one

Question 41

Does chlorine displace bromine and iodine?

Answer 41

Yes because it is more reactive

Question 42

Why does bromine displace iodine?

Answer 42

bc bromine is more reactive

Question 43

Where are transition metals on the periodic table?

Answer 43

Centre of periodic table

Question 44

What are the propeties of transition metals?

Answer 44

Transition metals are typical metals and have the properties you would expect of a proper metal- they are good conductor of heat and electricity and they are very dense, strong and shiny.
But they also have other properties:
Transition metals can have more than one ion
Transition metals are often coloured, and so compounds that contain them are colourful
Transition metal compounds often make good catalysts