The periodic table

Học bằng cách chơi

Trả lời những câu hỏi này để kiếm năng lượng, rồi câu cá và khám phá. Không cần tài khoản.

Dành cho nhà giáo dục: slide bài học, ghi chú ôn tập sẵn dùng cho The periodic table (Science, Chemistry) — dùng trong bài giảng của bạn, hoặc chạy chủ đề như một hoạt động lớp học tương tác để người học chơi như một trò chơi trực tiếp.

Ghi chú bài học

Arranging the Elements

Elements are arranged in order of increasing atomic number; each element has one proton more than the one before it.
The table is arranged in vertical columns called groups and horizontal rows called periods.
The period number tells you the number of electron shells an atom has (e.g. Period 3 elements have 3 shells).
The group number tells you the number of electrons in the outer shell (e.g. Group 1 elements have 1 outer electron).
Elements in the same group have similar chemical properties because they have the same number of outer electrons.
The group number can be used to predict how an element will react; elements in the same group react similarly.

History of the Periodic Table

Early periodic tables were arranged in order of atomic weight, before subatomic particles were discovered.
Early tables were incomplete: some elements were forced into gaps or placed in the wrong group because chemical properties were ignored.
In 1869 Dmitri Mendeleev arranged elements by increasing atomic weight but also considered their properties and those of their compounds.
Mendeleev left gaps in his table for elements that had not yet been discovered, rather than forcing elements to fit.
He used the properties of neighbouring elements to predict the properties of undiscovered elements, e.g. eka-silicon (now germanium).
When these predicted elements were later discovered and fitted the pattern, it confirmed his theories.
Mendeleev did not know about isotopes, which caused some inaccuracy in his table.
The modern Periodic Table uses atomic number to order elements, which fits Mendeleev's patterns.

Metals and Non-Metals

Elements can be divided into metals and non-metals; most elements are metals.
Metals react by losing electrons to form positive ions (cations).
Non-metals do not form positive ions; they gain electrons to form negative ions (anions) or are Group 0 elements.
Metalloids (semi-metals) display properties of both metals and non-metals.
Metallic character decreases across a period from left to right and increases down a group.
Metals have 1–3 outer shell electrons, are good conductors, form basic oxides and usually react with acids.
Non-metals have 4–7 outer shell electrons, are poor conductors, form acidic (or neutral) oxides and usually do not react with acids.
Metals are usually lustrous, malleable and have high melting points; non-metals are dull, brittle and have low melting points.

The metal/non-metal divide, with basic and acidic oxide regions

Group 0: The Noble Gases

Group 0 elements are called the noble gases; they are non-metals, monatomic, colourless and non-flammable gases at room temperature.
They have full outer shells of electrons, making them stable, unreactive and inert.
Helium has 2 outer electrons; the other noble gases have 8 outer electrons (so Group 0 is sometimes labelled Group 8).
Electronic configurations: He = 2, Ne = 2.8, Ar = 2.8.8, Kr = 2.8.18.8, Xe = 2.8.18.18.8.
Noble gases have very low melting and boiling points, which increase down the group as relative atomic mass increases.
The increase in boiling point is due to larger atoms having stronger intermolecular forces, so more energy is needed to overcome them.
Helium has the lowest boiling point of all elements (-269 ºC); radon boils at about -60 ºC.
Uses: helium fills balloons (less dense than air, does not burn); argon provides an inert atmosphere for welding and fills light bulbs; neon, argon and xenon are used in advertising signs.

The Periodic Table showing the location of the noble gases

Group 1: The Alkali Metals

Group 1 elements are known as the alkali metals: lithium, sodium, potassium, rubidium, caesium and francium.
They form alkaline solutions when they react with water (pH > 7).
They have similar chemical properties because they each have one electron in their outermost shell.
Physical properties: soft (can be cut with a knife), relatively low density and low melting points.
They are very reactive because they only need to lose one electron to become highly stable.
Softness increases down the group; melting points decrease down the group due to decreasing attractive forces between outer electrons and positive ions.
The first three alkali metals are less dense than water; potassium is an exception as it has a lower density than sodium.
They are stored in oil because they react readily with oxygen and water vapour in air.

Alkali metals occupy the far-left column; hydrogen is not presented as a Group 1 metal.

Reactions of the Alkali Metals

General reaction with water: group 1 metal + water → metal hydroxide + hydrogen.
Equation: 2M(s) + 2H₂O(l) → 2MOH(aq) + H₂(g), where M is Li, Na, K, Rb or Cs.
Lithium: relatively slow reaction, fizzes, moves on the surface of the water.
Sodium: more vigorous fizzing, moves rapidly on the surface, dissolves quickly.
Potassium: reacts more vigorously than sodium, burns with a lilac flame, moves very rapidly, dissolves very quickly.
Reaction with oxygen: alkali metals tarnish in air forming a dull metal oxide coating, e.g. 4Na(s) + O₂(g) → 2Na₂O(s).
Reaction with chlorine: alkali metals react vigorously when heated with chlorine to form metal chlorides, e.g. 2Na(s) + Cl₂(g) → 2NaCl(s).
Reactions become more vigorous down the group; rubidium, caesium and francium react even more vigorously with air and water.

Group 1: Reactivity and Electronic Configurations

Reactivity of Group 1 metals increases as you go down the group.
When a Group 1 atom reacts, it loses its single outer electron to form a 1+ ion.
The next shell down becomes the outermost shell and is already full, so the ion obtains noble gas configuration.
Going down the group, the number of electron shells increases by 1, so the outermost electron is further from the nucleus.
This means there are weaker forces of attraction between the outermost electron and the nucleus.
Less energy is required to overcome the weaker attraction, so the outer electron is lost more easily.
Therefore, the alkali metals get more reactive as you descend the group.

Group 7: The Halogens

Group 7 elements are the halogens: fluorine, chlorine, bromine, iodine and astatine.
They are non-metals that are poisonous and have seven electrons in their outermost shell.
Halogens are diatomic, forming molecules of pairs of atoms sharing electrons (single covalent bond), e.g. F₂, Cl₂.
When halogen atoms gain an electron they form -1 ions called halide ions.
At room temperature: fluorine and chlorine are gases, bromine is a liquid, iodine is a crumbly solid.
Colours become darker down the group: fluorine (yellow gas), chlorine (pale yellow-green gas), bromine (red-brown liquid), iodine (grey solid).
Melting and boiling points increase down the group due to increasing intermolecular forces as atoms get larger.
Test for chlorine: damp blue litmus paper is bleached white (it may turn red briefly); chlorine should be handled in a fume cupboard.

Group 7: Reactivity and Displacement

Reactivity of Group 7 non-metals decreases as you go down the group.
Going down the group, the number of shells increases, so the outer shell is further from the nucleus.
Halogens form negative ions by gaining an electron; the increased distance makes it harder to attract an electron.
Fluorine is the smallest halogen, so its outermost shell is closest to the nucleus, making it the most reactive.
A displacement reaction occurs when a more reactive halogen displaces a less reactive halogen from an aqueous solution of its halide.
Chlorine displaces bromine (solution becomes orange) and iodine (solution becomes brown); bromine displaces iodine (brown).
Example equations: Cl₂ + 2KBr → 2KCl + Br₂; Cl₂ + 2KI → 2KCl + I₂; Br₂ + 2KI → 2KBr + I₂.
Fluorine will displace all other halogens; astatine will be displaced by all halogens.

Halogen Displacement and Redox

Halogen displacement reactions are redox reactions: oxidation and reduction occur together.
Oxidation is loss of electrons; reduction is gain of electrons.
In Cl₂ + 2KI → 2KCl + I₂, the net ionic equation is Cl₂ + 2I⁻ → 2Cl⁻ + I₂.
Chlorine is reduced: Cl₂ + 2e⁻ → 2Cl⁻ (gain of electrons).
Iodide ions are oxidised: 2I⁻ → I₂ + 2e⁻ (loss of electrons).
The more reactive halogen undergoes reduction; the less reactive one undergoes oxidation.
Halogens react with metals to form ionic metal halide salts, e.g. 2Na + Cl₂ → 2NaCl; Ca + Br₂ → CaBr₂.
Halogens react with non-metals to form simple molecular covalent structures, e.g. hydrogen halides such as hydrogen chloride.

Slide

Step through every slide for this topic — plus flashcards and revision notes — with a free account.

ĐĂNG KÝ — MIỄN PHÍ ĐĂNG NHẬP

Câu hỏi luyện tập

Xem trước miễn phí — 8 trên 62 câu hỏi. Đăng ký để xem tất cả.

1.What is the name given to the elements in Group 0 of the periodic table?
Easy
- AAlkali metals
- BHalogens
- CNoble gases
- DTransition metals
2.What is the name given to the elements in Group 1 of the periodic table?
Easy
- ANoble gases
- BHalogens
- CTransition metals
- DAlkali metals
3.Which statement explains why Group 1 metals get more reactive further down the group?
Medium
- AThere is an increasing attraction between the outer electron and the nucleus
- BThere is less shielding of the outer electron so it is easier to lose
- CThere is a decreasing attraction between the outer electron and the nucleus so the electron is more easily lost
- DThe outer electron is closer to the nucleus and harder to lose
4.Which of the following is not true for the Group 1 metals?
Medium
- AThey are very reactive
- BThey have low melting points
- CThey have high densities
- DThey are soft
5.The noble gases are monatomic, meaning they exist as single atoms.
Easy
True or false?
6.The reactivity of the halogens increases as you go down Group 7.
Easy
True or false?
7.Which halogen is a red-brown liquid at room temperature?
Medium
- AFluorine
- BChlorine
- CBromine
- DIodine
8.Which of the following are properties of Group 1 metals? (select all that apply)
Medium
- AThey are soft and can be cut with a knife
- BThey have high melting points
- CThey have low densities
- DThey are very reactive
- EThey are poor conductors of electricity

Thêm câu hỏi

9.Which statements about the noble gases are correct? (select all that apply)
Medium
- AThey have full outer shells of electrons
- BThey are very reactive
- CThey are colourless gases at room temperature
- DThey exist as single atoms
- EThey readily form molecules
10.Match each group to its correct number of outer electrons.
Medium
- Group 1
- Group 7
- Group 0
- 1 outer electron
- 7 outer electrons
- Full outer shell
11.Which of the following statements about the noble gases are correct? (select all that apply)
Easy
- AThey are colourless gases at room temperature
- BThey are monatomic, existing as single atoms
- CThey have full outer shells of electrons
- DThey are highly reactive non-metals
- EThey readily form molecules with other elements
12.Which of the following are physical properties of the halogens? (select all that apply)
Medium
- AThey are non-metals
- BThey are diatomic molecules
- CThey are good conductors of electricity
- DThey are poisonous
- EThey are monatomic gases
13.Which statements about the alkali metals are correct? (select all that apply)
Medium
- AThey are soft and can be cut with a knife
- BThey have relatively low melting points
- CThey have high densities
- DThey are very reactive
- EThey form acidic solutions when they react with water
14.Match each halogen to its correct appearance at room temperature.
Medium
- Fluorine
- Chlorine
- Bromine
- Iodine
- Yellow gas
- Pale yellow-green gas
- Red-brown liquid
- Grey solid
15.Match each noble gas to its correct electronic configuration.
Medium
- Helium
- Neon
- Argon
- Krypton
- 2
- 2,8
- 2,8,8
- 2,8,18,8
16.Place the following Group 1 metals in order from least to most reactive.
Medium
- Lithium
- Sodium
- Potassium
- Caesium
17.Place the following halogens in order from most to least reactive.
Medium
- Chlorine
- Bromine
- Iodine
18.The noble gases are unreactive because they have full outer shells of electrons.
Easy
True or false?
19.Chlorine is more reactive than bromine.
Medium
True or false?
20.Sodium metal tarnishes in air to form a layer of sodium oxide on its surface. In one sample, 0.92 g of sodium combined with 0.32 g of oxygen. What is the empirical formula of this sodium oxide? (Relative atomic masses: Na = 23, O = 16)
Medium
- ANaO
- BNaO2
- CNa2O
- DNa2O2
21.A student adds a few drops of chlorine solution to a colourless sample of potassium bromide solution. The solution turns orange. Which statement best explains this observation?
Medium
- ABromine has displaced chlorine from solution because bromine is more reactive
- BChlorine has displaced bromine from solution because chlorine is more reactive
- CA solution of potassium chloride has formed, which is orange in colour
- DChlorine has been reduced to chloride ions, which are orange in solution
22.A student predicts the properties of rubidium, which lies below potassium in Group 1. Which of the following predictions are correct? (select all that apply)
Medium
- ARubidium is a soft grey solid
- BRubidium has a higher density than potassium
- CRubidium has a higher melting point than potassium
- DRubidium appears shiny when freshly cut
- ERubidium reacts less vigorously with water than potassium
23.Which of the following correctly shows the group and period in which sodium is located?
Medium
- AGroup 1, Period 3
- BGroup 1, Period 4
- CGroup 0, Period 3
- DGroup 0, Period 4
24.The noble gases have boiling points that are all below 0 °C.
Easy
True or false?
25.A sample of argon is placed in a low energy light bulb. Which property of argon makes it suitable for this use?
Medium
- AIt is chemically inert and glows brightly when a high potential difference is applied
- BIt is less dense than air and does not burn
- CIt is a good conductor of electricity
- DIt reacts with the metal filament to produce light
26.Solid lithium reacts with cold water to form an aqueous solution of lithium hydroxide and hydrogen gas. Which is the correct balanced chemical equation for the reaction?
Medium
- ALi (s) + H2O (g) → LiOH (aq) + H2 (g)
- BLi (s) + H2O (l) → LiOH (aq) + H2 (g)
- C2Li (s) + 2H2O (l) → 2LiOH (aq) + H2 (g)
- D2Li (s) + 2H2O (g) → 2LiOH (aq) + H2 (g)
27.Match each halogen to the colour it produces in aqueous solution.
Medium
- Chlorine
- Bromine
- Iodine
- Pale green
- Orange
- Dark brown
28.A student tests three halide solutions with different halogen solutions. Place the following halogens in order from most reactive to least reactive.
Medium
- Iodine
- Chlorine
- Bromine
29.A teacher adds bromine solution to a colourless sample of potassium iodide solution. Which observation and explanation are both correct?
Hard
- AThe solution turns orange because bromine is less reactive than iodine
- BThe solution turns brown because bromine displaces iodine, which is less reactive
- CNo reaction occurs because iodine is more reactive than bromine
- DThe solution turns pale green because chlorine is formed
30.A student is given an unknown colourless gas and told it may be chlorine. Which of the following are valid tests or observations that could help identify chlorine? (select all that apply)
Medium
- ADamp blue litmus paper is bleached white
- BThe gas is pale yellow-green in colour
- CThe gas has a smell like swimming pools
- DThe gas relights a glowing splint
- EThe gas turns limewater milky
31.Which of the following is not a property of Group 1 metals?
Medium
- AThey are soft
- BThey have relatively high melting points
- CThey are very reactive
- DThey have relatively low densities
32.The graph of boiling point against relative atomic mass for the noble gases shows a steady increase from helium to radon. Which statement best explains this trend?
Hard
- AThe atoms get larger and have a greater relative atomic mass, so the intermolecular forces increase and more energy is needed to overcome them
- BThe atoms get smaller, so the intermolecular forces decrease and less energy is needed to overcome them
- CThe atoms form stronger covalent bonds down the group, so more energy is needed to break them
- DThe atoms gain electrons more easily down the group, so more energy is released
33.Halogens exist as diatomic molecules, such as Cl2, in which the two atoms share electrons in a single covalent bond.
Medium
True or false?
34.A teacher adds bromine solution to a colourless sample of potassium iodide solution in a test tube. What is the colour of the solution after the reaction, and why?
Medium
- AThe solution turns brown because iodine is formed.
- BThe solution turns orange because bromine is formed.
- CThe solution stays colourless because no reaction occurs.
- DThe solution turns pale green because chlorine is formed.
35.Which of the following observations would you expect when chlorine solution is added to separate samples of potassium bromide and potassium iodide solutions? (select all that apply)
Medium
- AThe potassium bromide solution turns orange.
- BThe potassium iodide solution turns brown.
- CThe potassium bromide solution stays colourless.
- DThe potassium iodide solution turns pale green.
- EA white precipitate forms in both solutions.
36.In a halogen displacement reaction, the more reactive halogen is oxidised.
Easy
True or false?
37.Match each halogen to its state at room temperature.
Medium
- Chlorine
- Bromine
- Iodine
- Gas
- Liquid
- Solid
38.Place the following halogens in order of decreasing reactivity (most reactive first).
Medium
- Chlorine
- Bromine
- Iodine
39.A student adds chlorine solution to a colourless solution of potassium iodide. Which half-equation correctly represents the reduction that occurs?
Medium
- ACl₂ + 2e⁻ → 2Cl⁻
- B2I⁻ → I₂ + 2e⁻
- CCl₂ → 2Cl⁻ + 2e⁻
- D2Cl⁻ → Cl₂ + 2e⁻
40.Which safety precaution is most important when demonstrating this experiment?
Medium
- AWear safety goggles and use a safety screen.
- BUse a Bunsen burner to heat the water.
- CAdd the metals quickly using bare hands.
- DPerform the experiment in a fume cupboard.
41.Complete the sentence about the characteristic reaction of Group 1 elements.
Easy
Group 1 elements react with ____ to form ____ solutions and hydrogen.
42.Calculate the empirical formula of sodium oxide given that 0.92 g of sodium combined with 0.32 g of oxygen. (Relative atomic masses: Na = 23, O = 16). Give your answer as the value of x in NaxO.
Medium
43.The boiling point of helium is -269 °C and the boiling point of radon is -60 °C. Estimate the boiling point, in °C, of krypton, which lies between argon and xenon in Group 0. Give your answer to the nearest whole number.
Medium
44.Complete the word equation for the reaction between potassium and water.
Easy
potassium + water → ____ + ____
45.Complete the sentence about a characteristic reaction of the Group 1 elements.
Easy
Group 1 elements react with ____ to form ____ solutions and hydrogen.
46.Use the words to complete the sentences about francium and rubidium. Each word may be used once, more than once or not at all.
Medium
The distance between the outermost electron of francium and its nucleus is ____ than that of rubidium. This means that the forces of attraction in francium are ____. Therefore, ____ energy is required to overcome the forces of attraction in francium.
47.Sodium has 11 electrons. How many electrons are in the outermost shell of a sodium atom?
Medium
48.Potassium has 19 electrons. Give the electronic configuration of a potassium atom.
Medium
49.Helium has the lowest boiling point of all known elements. State its boiling point in °C.
Medium
50.Radon boils at about -60 °C. Estimate the boiling point, in °C, of xenon, which lies between krypton and radon in Group 0.
Medium
51.Complete the sentences about the noble gases.
Easy
The noble gases are ____ (they exist as single atoms) and are ____ gases at room temperature. They are unreactive because they have ____ outer shells of electrons.
52.Give the electronic configuration of a krypton atom.
Medium
53.Explain why francium is more reactive than rubidium.
Medium
54.Explain, in terms of electronic configurations, why the reactivity of the Group 1 metals increases from lithium to sodium to potassium.
Hard
55.In an experiment, equal-sized pieces of lithium, sodium and potassium are added to separate samples of water. The results show that the effervescence is slow for lithium, fast for sodium and very fast for potassium. Explain, in terms of electronic configurations, the increase in reactivity from lithium to sodium to potassium.
Hard
56.Chlorine solution is added to colourless potassium iodide solution. The solution turns brown. Explain, using half equations, why this displacement reaction is a redox reaction.
Hard
57.State how a Group 1 metal atom, M, becomes a Group 1 metal ion, M+.
Medium
58.Calculate the empirical formula of sodium oxide given that 0.92 g of sodium combined with 0.32 g of oxygen. (Relative atomic masses: Na = 23, O = 16). Give your answer as the value of x in NaxO.
Medium
- A3
- B2
- C4
- D1
59.The boiling point of helium is -269 °C and the boiling point of radon is -60 °C. Estimate the boiling point, in °C, of krypton, which lies between argon and xenon in Group 0. Give your answer to the nearest whole number.
Medium
- A-153 °C
- B-138 °C
- C-123 °C
- D-168 °C
60.Sodium has 11 electrons. How many electrons are in the outermost shell of a sodium atom?
Medium
- A1
- B3
- C0
- D2
61.Helium has the lowest boiling point of all known elements. State its boiling point in °C.
Medium
- A-296 °C
- B-269 °C
- C-215 °C
- D-242 °C
62.Radon boils at about -60 °C. Estimate the boiling point, in °C, of xenon, which lies between krypton and radon in Group 0.
Medium
- A-86 °C
- B-97 °C
- C-119 °C
- D-108 °C

Thẻ ghi nhớ

What name is given to the elements in Group 0 of the periodic table?

The noble gases.

Why are the noble gases unreactive?

They have full outer shells of electrons, which is extremely stable, so they do not need to lose, gain or share electrons.

What is the electronic configuration of helium?

2 (it has 2 electrons in its outer shell).

What is the electronic configuration of neon?

2.8

What is the electronic configuration of argon?

2.8.8

What is the trend in boiling points of the noble gases as you go down the group?

Boiling points increase down the group because relative atomic mass increases, leading to stronger intermolecular forces that need more energy to overcome.

Why do the noble gases have low densities?

They are gases at room temperature, so their individual atoms are widely spaced apart.

Give one use of argon.

Argon is used to provide an inert atmosphere for welding and to fill light bulbs.

What is the name of Group 1 in the periodic table?

The alkali metals.

List the first three alkali metals in order of increasing reactivity.

Lithium, sodium, potassium.

What are the general products when a Group 1 metal reacts with water?

A metal hydroxide and hydrogen. For example: 2Na(s) + 2H₂O(l) → 2NaOH(aq) + H₂(g).

Describe two observations when lithium is added to water.

Lithium fizzes and moves on the surface of the water.

Describe two observations when sodium is added to water.

Sodium fizzes vigorously and moves rapidly on the surface of the water.

Describe two observations when potassium is added to water.

Potassium reacts vigorously, burns with a lilac flame and moves very rapidly on the surface.

Why does the reactivity of Group 1 metals increase as you go down the group?

The outermost electron is further from the nucleus, so the forces of attraction are weaker and less energy is needed to lose the electron.

What is the general equation for the reaction of a Group 1 metal with oxygen?

4M(s) + O₂(g) → 2M₂O(s), where M is a Group 1 metal. For example: 4Na(s) + O₂(g) → 2Na₂O(s).

What is the general equation for the reaction of a Group 1 metal with chlorine?

2M(s) + Cl₂(g) → 2MCl(s), where M is a Group 1 metal. For example: 2Na(s) + Cl₂(g) → 2NaCl(s).

Why are Group 1 metals stored in oil?

They react readily with oxygen and water vapour in the air, so oil prevents them from reacting.

What is the name of Group 7 in the periodic table?

The halogens.

List the halogens in order from top to bottom of Group 7.

Fluorine, chlorine, bromine, iodine, astatine.

What is the trend in reactivity of the halogens down Group 7?

Reactivity decreases down the group.

Why are halogens less reactive as you go down Group 7?

The outer shell is further from the nucleus, so the force of attraction is weaker and it is harder for the atom to gain an electron.

What is the test for chlorine gas?

Damp blue litmus paper is bleached white (it may turn red briefly first).

What is a displacement reaction?

A reaction where a more reactive halogen displaces a less reactive halogen from an aqueous solution of its halide.

What is the general equation for the reaction of a halogen with a metal?

Halogen + metal → metal halide. For example: 2Na + Cl₂ → 2NaCl.

Unlock all 62 questions, flashcards & more

Tạo tài khoản miễn phí để xem mọi câu hỏi, slide, thẻ ghi nhớ và ghi chú ôn tập cho chủ đề này.

ĐĂNG KÝ — MIỄN PHÍ ĐĂNG NHẬP

Đề thi cũ

Luyện đề thi cũ cho chủ đề này sắp ra mắt.

Sắp ra mắt