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| Question | Answer |
|---|---|
| Who made the first step towards the modern periodic table? | John Dalton |
| How did John Dalton organise elements? | by atomic mass |
| Who built on John Dalton's ideas? | John Newlands |
| What did John Newlands contribute to the development of the periodic table? | he noticed that the properties of every 8th element seemed similar |
| What did John Newlands name the pattern he discovered? | the law of octaves |
| What mistake was made by John Newlands? | he assumed that all the elements had been found |
| What was the consequence of John Newlands' mistake? | his table only worked up to calcium after which it broke down |
| Who solved the problem created by John Newlands' mistake? | Dimitri Mendeleev |
| How many elements had been identified when Mendeleev created a periodic table? | around 50 |
| What order did Mendeleev use for organising elements? | atomic mass |
| What did Mendeleev realise? | that not all elements had been discovered |
| What did Mendeleev do differently? | he organised elements based on shared properties leaving gaps |
| How did Mendeleev account for the gaps? | he predicted that some elements had yet to be discovered and predicted their properties using known elements |
| What issue did Mendeleev encounter with the order of elements? | organising elements by their atomic mass made it impossible to keep elements with the same properties together |
| Where there was a conflict between properties and atomic mass, which one did Mendeleev choose? | properties |
| What is used to order elements in the modern periodic table? | atomic number, the number of protons |
| What is atomic number? | atomic number is the number of protons |
| What caused the problem encountered by Mendeleev? | isotopes |
| Why is the table of elements called the periodic table? | it is named after the regular repeating patterns in the properties of elements |
| Question | Answer | |
|---|---|---|
| What determines the order of the elements on the periodic table? | in order of atomic number which is the number of protons | |
| How many main groups are there on the periodic table? | 8 | |
| What do the elements in groups have in common? | they share similar properties | |
| Why do elements of a group react in similar ways? | because they have the same number of electrons in the outer shell | |
| What does the group number say about the electrons of an element? | the group number is the same as the number of electrons in the outer shell | |
| How many electrons in the outer shell of Group II elements? | 2 electrons | |
| How many electrons in the outer shell of Group VI elements? | 6 electroms | |
| What do metals tend to do when reacting? | they tend to lose electrons and become positive ions | |
| Which groups are metals that form positive ions? | group 1, 2, and 3 | |
| How many electrons will Group I metals lose and what will their charge be? | group I metals lose 1 electron and the ion becomes 1+ | |
| What ion does sodium (Na) form? | sodium is in group 1 and so loses 1 electron becoming Na1+ | |
| How many electrons will Group II metals lose and what will their charge be? | group II metals lose 2 electrons and the ion becomes 2+ | |
| What ion does magnesium (Mg) form? | magnesium is in group 2 and so loses 2 electrons becoming Mg2+ | |
| What do non-metals tend to do when reacting? | they tend to gain electrons and become negative ions | |
| Which groups are non-metals that form negative ions? | group 5, 6, and 7 | |
| How many electrons will Group VII non-metals gain and what will their charge be? | group VII non-metals gain 1 electron and the ion becomes 1- | |
| What ion does chlorine (Cl) form? | chlorine is in group 7 and so gains 1 electron becoming Cl1- | |
| How many electrons will Group VI non-metals gain and what will their charge be? | group VI non-metals gain 2 electrons and the ion becomes 2- | |
| What ion does oxygen (O) form? | oxygen is in group 6 and so gains 2 electrons becoming O2- | |
| How many electrons are found in the outer shell of group 0 elements? | 8 electrons in all except Helium which has only 2 electrons | |
| What are the consequences of group 0 having a full outer shell? | the elements of group 0 are very stable | |
| Why are group 0 elements so unreactive? | because their outer shells are full not needing more electrons for a complete outer shell | |
| Why do group 0 elements exist as single atoms? | because their outer shells are already full so they do not need to bond to other atoms to create a complete outer shell | |
| What does the term monatomic mean? | an element that exists as single atoms is described as monatomic | |
| Do noble gases react? | they tend not to react although some of the large noble gases have been reacted with the most reactive elements like flourine and oxygen | |
| State an example of a compound formed with group 0 elements. | XeF6 and XeO4 | |
| What is the boiling point trend in group 0? | boiling point increases going down the group |
| Question | Answer |
|---|---|
| What is the name of Group I? | the alkali metals |
| Name the first three members of group I in order. |
• Lithium Li • Sodium Na • Potassium K |
| How are group I metals stored? | in oil |
| Why are group I metals stored in oil? | because they are highly reactive and will react with oxygen in the air |
| Describe the physical properties of the group I metals. |
• shiny (like other metals) • soft (can be cut with a knife) • low density (float on water) • low boiling points • low melting points |
| Describe the density of Group I metals. |
• they are low compared to other metals • Li, Na and K are less dense than water so float on water |
| Describe the trend with boiling and melting points of group I elements. | boiling and melting points decrease down the group |
| How do group I metals burn in oxygen? | they react vigorously forming white smoke of their oxides |
| Write an equation for sodium reacting with oxygen. | 4Na + O2 → 2Na2O |
| Write the general equation for a group I metal reacting with oxygen. | 4X + O2 → 2X2O |
| What causes the properties of the group I metals? | the electronic structure with one electron in the outer shell |
| Why are group I metals so reactive? | they only need to lose one electron to get to the stable electronic structure of a noble gas |
| How does reactivity change in group I | elements become more reactive going down the group |
| Why does reactivity increase down a group? | because it becomes easier to lose the single electron in the outer shell as the atom gets larger |
| Which is the least reactive group I metal? | Lithium Li |
| Which is the most reactive group I metal? | Francium Fr |
| What ion does a group I metal form? | they all form a 1+ ion eg Na1+ and Li1+ |
| What tyoe of compounds do group I metals form? | they ALWAYS form ionic compounds |
| How do Lithium, Sodium and Potassium react with water? |
• Lithium floats on water, moving around slowly and fizzing gently • Sodium floats on water, moving around quickly and fizzing vigorously • Potassium bursts into flames (lilac) while it speeds round on water |
| What gas is produced when a group I metal reacts with water? | hydrogen gas H2 |
| Write the equation for lithium reacting with water. | 2Li(s) + 2H2O(l) → 2LiOH(aq) + H2(g) |
| Write the general equation for a group I metal reacting with water. | 2X(s) + 2H2O(l) → 2XOH(aq) + H2(g) |
| What do group I metals produce when reacting with chlorine? | metal chlorides |
| What do metal chlorides look like? | they are white, metal solids |
| Write the equation for sodium reacting with chlorine. | 2Na + Cl2 → 2NaCl |
| Write the general equation for a group I metal reacting with chlorine. | 2X + Cl2 → 2XCl |
| Are group I metal chlorides soluble or insoluble in water? | very soluble |
| What colour are solutions of group I metal chlorides in water? | they are colourless |
| Question | Answer |
|---|---|
| What in the name of group 7 elements? | the halogens |
| Describe the halogens. | toxic non-metals that produce colour vapours |
| List the properties of non-metals. |
• low melting points • low boiling points • poor conductors of heat • poor conductors of electricity |
| What is the trend for the melting and boiling points of the halogens? | both increase going down the group |
| Do halogens as elements exist as molecules or atoms? | all halogens are diatomic molecules |
| What are diatomic molecules? | a molecule made up as two atoms |
| What are the bonds in the diatomic molecules of halogens? | covalent bonds |
| What electronic arrangement do halogens share? | they all have 7 electrons in their outer shell |
| What do halogen atoms need to have a stable outer shell? | they need to gain a single electron |
| How does reactivity change in halogens? | they get less reactive going down the group |
| Write the reaction for hydrogen reacting with fluorine? | H2(g) + F2(g) → 2HF(g) |
| What types of molecules do halogens form when they react with non-metals? | covalent compounds |
| What happens to the electronic arrangement of halogens when they react with metals? | they gain a single electron to become a 1- ion |
| What is displacement in chemical reactions? | one element replaces another element in a compound |
| How does displacement work with halogens? | a more reactive halogen will displace a less reactive halogen from solutions of its salts |
| Write the equation of chlorine reacting with potassium bromide? | Cl2(aq) + KBr(aq) → Br2(aq) + KCl(aq) |
| How we describe what chlorine has done to bromine in the reaction of chlorine with potassium bromide? | chlorine has displaced the bromine in potassium bromide |
| Why does chlorine displace bromine in the reaction of chlorine with potassium bromide? | because chlorine in more reactive than bromine |
| What happens when bromine reacts with potassium chloride? | absolutely nothing |
| Why does nothing happen with bromine is reacted with potassium chloride? | because chlorine is more reactive than bromine, bromine cannot displace the chlorine in potassium chloride |
| What is the colour of the halogen solutions? |
• chlorine solution Cl2(aq) is very pale green • bromine solution Br2(aq) is yellow • iodine solution I2(aq) is darker red/brown |
| Which halogens with fluorine displace? | fluorine is the most reactive halogen so will displace all other halogens |
| Why can one not carry out experiment with fluorine solution? | fluorine reacts extremely violently with water |
| Question | Answer |
|---|---|
| How does reactivity change in group I? | elements get more reactive going down group I |
| How does reactivity change in group VII? | elements get less reactive going down group VII |
| How do shells change on the periodic table? |
• the period number is equal to the number of shells in an atom of an element • the shells increase down the periods by one each period |
| What is the effect of the shells increasing down the periods? |
• larger atoms (more shells) lose electrons more easily going down a group • larger atoms (more shells) gain electrons less easily going down a group |
| Why do larger atoms (more shells) lose electrons more easily going down a group |
• the electrons are further away from the attractive force of the nucleus • the inner shells of electrons 'shield' the outer electrons from the positive charge of the nucleus |
| What happens to the electrons when alkali metals react? | an alkali metal tends to lose an electron when forming a chemical bond |
| What happens to the electrons when halogens react? | a halogen tends to gain an electron when forming a chemical bond |
| Name the factors that affect reactivity down a group. |
• the size of the atom • the shielding effect of inner electrons • the nuclear charge |
| What is the effect of the size of the atom on reactivity? |
• the outer electrons get further away from the nucleus as the atom increases in size • the electrostatic attraction of the nucleus gets weaker the further away the outer electron is • for group I, this means it is easier to lose the outer electron • for group VII, this means that it is harder to attract outer electrons |
| What is the effect of shielding on reactivity? |
• the shielding of inner electrons reduces the attraction between the electron and the nucleus • for group I, this means it is easier to lose the outer electron • for group VII, this means that it is harder to attract outer electrons |
| What is the effect of nuclear charge on reactivity? |
• the size of the positive charge of the nuclues increases down a group as the number of protons increases • this increases the positive charge of the nucleus but this effect is usually cancelled out by shielding and the distance from the nucleus |
| How easy is it to remove electrons from group I elements? | it gets easier to remove an electron from the outer shell going down the group because the outer shell gets further away and shielding increases weakening the electrostatic force with which it is held by the nucleus |
| How does the ease of removing an electron relate to reactivity for Group I? | the easier it is to remove an electron, the higher the reactivity of an element |
| Compare how easy it is for the elements of group VII to gain electrons? | it gets harder to gain an electron going down the group because the outer shell gets further away and shielding increases reducing the ability of the nucleus to attract electrons |
| How does the ease of attracting an electron relate to reactivity for Group VII? | the harder it is to attract an electron, the lower the reactivity of an element |
| Why is chlorine less reactive than fluorine when chlorine has a greater positive nuclear charge than fluorine? | the effect of the increased nuclear charge is outweighed by the shielding of inner electrons and the distance of electrons from the nucleus |
| Question | Answer |
|---|---|
| What is an alloy? | a mixture of metals |
| Name an alloy and its component elements. | brass is a mixture of copper and zinc |
| Where are the transition elements? | between group 2 and 3 |
| Are the transition elements metals or non-metals? | they are all metals |
| Name some transition metals. | gold (Au), silver (Ag), iron (Fe), platinum (Pt) and copper (Cu) |
| Name the physical properties of the transition elements. |
• they are good conductors of heat and electricity • they are hard and strong • they have high densities • they have high melting points - except mercury which is liquid at room temperature |
| How do the melting points of transition elements compare with the melting points of alkali metals? | the transition elements have much higher melting points than those of alkali metals |
| How do the physical properties other than melting point compare for transition elements and alkali metals? | the transition elements are harder, stronger and much more dense than the alkali metals |
| How does the reactivity of the alkali metals compare with the transition metals? | the alkali metals are much more reactive than the transition elements |
| How does copper foil react with oxygen gas? | copper foil has to be heated strongly before it reacts with oxygen with a black coating of copper (II) oxide forming on the surface |
| Write the equation for the reaction of copper with oxygen. | Cu(s) + O2(g) → 2CuO(s) |
| How does iron react with chlorine gas? | the chlorine gas has to be passed over iron and heated strongly inside a horizontal pyrex tube to form red iron (III) chloride |
| Write the equation for the reaction of iron with chlorine. | Fe(s) + Cl2(g) → FeCl2(s) |
| What makes transition metals useful as structural materials? | they corrode very slowly |
| Name the main metal used in the construction industry. | iron, usually as steel |
| What is the problem with iron (steel) used in construction? | when it rusts, it weakens structures |
| What is noticeable about most transition element compounds? | they are coloured |
| State the colour for each compound. •copper(II) sulphate •nickel(II) carbonate •chromium(III) oxide •manganese(II) chloride |
The colour is •copper(II) sulphate blue •nickel(II) carbonate pale green •chromium(III) oxide dark green •manganese(II) chloride pale pink |
| State the charge of the transition element in each compound. •copper(II) sulphate •nickel(II) carbonate •chromium(III) oxide •manganese(II) chloride |
The charge is •copper Cu2+ •nickel Ni2+ •chromium Cr3+ •manganese Mn2+ |
| What gives the compounds of transition elements their colours? | the ions they form |
| Why can one transition element have different colours in compounds? | because the same element will form multiple ions |
| What ions can copper form? | Cu1+ and Cu2+ |
| What ions can iron form? | Fe2+ and Fe3+ |
| What are the colours of the ions of iron? |
•Fe2+ is green •Fe3+ is reddish-brown |
| How are the different ions indicated in chemical names? | using Roman numerals, eg copper(I) means Cu1+2+ |
| What important role is fulfilled by transition elements in the chemical industry? | as catalysts |
| Name two examples of transition elements being used in industry as catalysts. |
•nickel Ni in the manufacture of margarine •iron Fe in the Haber process to produce ammonia |
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