Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
OCR 21stC science C4
OCR 21st Century Science C4
| Question | Answer | ||
|---|---|---|---|
| Relative atomic mass is the comparison of an atom's mass to []'s (the []est) | hydrogen's--lightest--. | ||
| In a periodic table, a [] of elements is a vertical column | group--. | ||
| The elements in a group in the periodic table have similar | properties. For example, group 1 contains sodium and other very reactive []s while group 7 contains lithium and other very reactive []-[]s | metals-- non-metals--. | |
| A row of element in the periodic table is called a | period. | ||
| Chemical symbol for lithium: | Li | ||
| Chemical symbol for sodium: | Na. | ||
| Chemical symbol for potassium: | K. | ||
| When alkali metals are freshly cut they are | shiny, but they tarnish rapidly in []t []r due to reaction with [] | moist air--oxygen--. | |
| Lithium, sodium and potassium all react vigorously with [] and [] | air and water. | ||
| Alkali metals react with water to form [] gas and an [] solution of a [] | hydrogen--alkaline--hydroxide--; the formula is given as H+M[] where M represents a group [] metal | OH--1--. | |
| The group 1 metals are refered to as | alkali metals | ||
| A[] []s vigorously react with chlorine to form []less, []ine s[]s with the formula [] | Alkali metals--colourless, crystalline salts--MCl--. | ||
| The shiny surface of sodium tarnishes []er than that of lithium, while sodium tarnishes [] than potassium; | quicker--slower; this shows the increasing []ty of the metals as we go down the group | reactivity--. | |
| Because, the alkali metals are so []e, care has to be taken when using them | reactive--. They must not be t[]ed as they will react with [] in [] on the [] | touched--water--sweat--skin--. G[]es may be used and g[]s should be worn | gloves--goggles--. |
| The group 7 elements are also known as the | halogens. | ||
| Chemical symbol of chlorine: | Cl. | ||
| Chemical symbol of bromine: | Br. | ||
| Chemical symbol of iodine: | I. | ||
| The halogens consist of []c molecules | diatomic--. | ||
| As you go down the group, halogens become [] reactive | less. Flourine, at the top of the group, is the most reactive halogen. It is very dangerous and can cause severe chemical b[]s on contact with skin. | burns--. | |
| The relative reactivity of halogens can be shown by looking at [] reactions | displacement--. | ||
| |Displacement Reactions| When chorine (gas or dissolved in water) is added to sodium bromide solution, the [] takes the place of the [] because its more [] and displaces [] from the [] []. | chlorine--bromine--reactive--bromine--sodium bromide--. The solution turns brown, the brown colour being the []d []. The chlorine has gone to form [] [] | displace bromine--sodium chloride--. chlorine + sodium bromide --> | sodium chloride + bromine. |
| Halogens are very []e and p[], hence care must be taken | reactive--poisonous--. Chlorine is used only in a []e []d, iodine should not be handled as it wil damage the []; g[]s may be used, and g[]s should be worn | fume cupboard--skin--gloves--goggles--. | |
| The state symbol (s) means | solid. | ||
| The state symbol (l) means | liquid. | ||
| The state symbol (g) means | gas. | ||
| The state symbol (aq) means | aqueous (dissolved in water). | ||
| An atom is a composition of protons and neutrons in a very small central [] and electrons arranged in []s around the nucleus | nucleus--shells--. | ||
| Protons and neutrons have the same m[], which is about [] times larger than an electron's. | mass--2000--. An electron's mass is generally taken as 0 for being neglible. | ||
| The elements in the periodic table are arranged according to the their [] number | atomic--. | ||
| All the atoms of the same element have the same number of p[] | protons. The number of protons will be equal to the number of []s | electrons--. | |
| Some elements emit distinctive []e colours when []ed | flame--heated--, e.g. l[]um, s[]um and p[]um | lithium, sodium and potassium. | |
| The light emitted from a particular element gives a characteristic [] s[] | line spectrum. | ||
| Scientists have used line spectra to discover new e[]ts. In fact the discovery of some elements, such as the r[]dium and c[]ium, owuld not have been possible if not of spectroscopy | elements--rubidium--caesium--. The element helium was discovered by studying line spectra emitted by the [] | Sun. | |
| The discovery of some elements depended on the development of new []cal t[]s | practical techniques-- e.g. s[]opy | spectroscopy--. | |
| Electrons are contained in s[]s around the []s, also called []y l[]s | shells--nucleus--energy levels. A shell (or [] level) fills with electrons across a [] | energy--period-- (thus elements in the same group have the same number of electrons in their outer shell, this number being the group number). | |
| Elements in the same [] have the same number of electrons in their outer shell and this number is the [] number | group--group--. | ||
| When lithium is added to water it []s, f[]ing steadily and becomes []er until it eventually d[]rs | floats--fizzing--smaller--dissappears--. | ||
| Protons has a relative mass of [] unit(s), while neutrons have one of [] unit(s) | 1--1--. The relative atomic mass is thus the number of [] + number of [] | protons--neutrons--. | |
| The relative atomic mass - number of protons = | number of neutrons. Atomic number = number of []s = number of []s | protons--electrons--. | |
| Molten (i.e. melted) compounds of metals with non-metals c[] electricity, which is eevidence that they are mde up of []ed particles called []s | conduct--charged--ions--. | ||
| An ion is an [] (or group of []s) which has gained or lost []s and thus has an overall []e | atom--atoms--electrons--charge. | ||
| The alkali metals (group 1) form ionic compounds when they react with []-[]s; their ions have a []ive charge of [] | non-metals --positive--1--. For example, sodium forms sodium ions, Na^[] (M^n+ has n electrons [] than an a[] its type) | +--less--atom--. | |
| The halogens (group 7) form ionic compounds when they react with []s; their ions have a []ive charge of [] | metals --negative--1--. For example, chlorine forms chlorine ions, Cl^[] (M^n- has n electrons [] than an a[] its type) | - --more--atom--. | |
| If one knows the charges on the ions in an []ic c[]d, one can work out its formula | ionic--compound--. To do so, simply balance b[]e the positive and negative []es: e.g. calcium has ion Ca^2+ while chlorine has ion Cl^-, meaning the formula is [] | balance--charges--CaCl2[ss]--. | |
| If one has the formula of an []ic c[]d and the charge of one of the two ions, one can work out the charge of the other ion | ionic--compound--. To do so, simply look at what b[]es the c[]es: eg. take Na2O, knowing a sodium ion is Na^+ - the oxygen ion must be [] | balaces--charges-- O^2- --. | |
| As group 7 elements are non-metals, the compounds of halogens with alkali metals are []ic | ionic--. | ||
| Solid ionic compounds form c[]s because ions are arrange in a r[]r l[]e | crystals--regular--lattice--. | ||
| [] ionic compounds do not conduct electricity as the ions are held firmly in []ce; they cannot [] to conduct the electric current | solid--place--move--. | ||
| When an ionic compound melts, the charged ions are free to [] independently in the liquid, meaning that []en ions do [] electricity | move--molten--conduct--. | ||
| When a crystal of an ionic compound dissolves, the ions s[]e, meaning that the ions are free to [] inependently in the liquid, so a solution of an ionic compound in water []s electricity | separate-moves--conducts--. | ||
| =Line spectra= All atoms give off []t when heated, although sometimes this light is not visible to the human eye. | light--.A p[]sm is used to s[]t the light to form a s[], and each element has a distinctive l[] s[] [#b4#] | ||
| The innermost (first) shell can hold up to [] electron while the second shell can hold up to [] | 2--8--; for the first 20 elements, the third shell can hold up to [] | 8--. | |
| An electron configuration of 2 electrons then 8 then 8 would be shown as: 2[]8[]8 | 2.8.8 -- or through dots in circles. [#C6#] | ||
| At room temperature and pressure, chlorine's state is [] and is y[]-[] in colour | gas--yellow-green--. At room temperature and pressure, bromine's state is [] and it's []-b[] in colour | liquid--red-brown--. At room temperature and pressure, iodine's state is as a [] and it's colour is a d[] []e | solid--dark--purple--. |
| At room temperature and pressure, Bromine, unlike gas chlorine, is a liquid -- coloured red-brown. When it's a gas, it's []wish-b[] in colour | yellowish-brown--. | ||
| At room temperature and pressure, iodine is a dark purple solid, while as a gas it is [] []e | dark purple--. | ||
| Group 1 elements are also known as [] me[]s | alkali metals. | ||
| Lithium, Sodium, Potassium, Rubidium and Caesium are all in group [] of the Periodic table | 1. | ||
| All the alkali metals react v[]ly with cold water. In each reaction [] gas is given off and the metal []de is produced | vigorously--hydrogen--hydroxide--. The state of the alkali metals is obviously [] while the metal hydroxide's are a[] al[]ne []tions | solid--aqueous--alkaline--solutions--. | |
| All the alkali metals react vigorously with cold water. The s[] and vi[] of the reaction increases as you go 1 the group | speed--violence--. This shows the []ty of the alkali metals increases as you go down Group 1 | reactivity--. | |
| When Sodium is added to water, the sodium []s to form a [] that moves around on the s[] | melts--ball--surface--. It []es []ly, and the hydrogen produced may b[] with an []e []e before the sodium d[]s | fizzes rapidly--burn--orange flame--disappears--. | |
| When potassium is added to water, the metals []s and []s--it moves around []ly on the []e of the water--the hydrogen []es []tly | melts--floats--quickly--surface--ignites instantly--. The metal is also set on []e, with s[]s and a l[] flame; there is sometimes a small e[] at the end of the reaction | fire--sparks--lilac--explosion--. | |
| lithiu + water → | lithium hydroxide + hydrogen, or as a chemical equation: | 2Li(s) + 2H₂O(l) → 2LiOH(aq) + H₂(g) | |
| sodium + water → | sodium hydroxide + hydrogen, or as a chemical equation: | 2Na(s) + 2H₂O(l)→ 2NaOH(aq) + H₂(g) | |
| potassium + water → | potassium hydroxide + hydrogen, or as a chemical equation: | 2K(s) + 2H₂O(l) → 2KOH(aq) + H₂(g). | |
| The trend in reactivity for halogens (decreasing as you descend) can be shown in []ment reactions where the [] reactive element displaces the [] reactive one | displacement--more--less--, and is evident in their reactions with [] m[]s and with i[] | alkali metals--iron--. | |
| Because the halogens are very []e and []us, care must be taken when using them | reactive--poisonous--. Chlorine is used only in a f[] c[]. Iodine should not be h[]ed (it will damage the []n) | fume cupboard--handled--skin--. G[]s may be used and g[]s must be worn | gloves--goggles--. |
| The chemical formua for Hydrogen: | H₂. | ||
| The chemical formula for chloride is [] as it's an []n | C⁻ as it's an anion-- (though it may not always be shown as such, e.g. 2NaCl). The chemical formula for bromide is [] while the chemical formula for iodide is [] | anion-- Br⁻ -- I⁻ --. Chlorides, bromides and iodides made up the group known as the | halides. |
| Atoms of each element have a different [] number (i.e. number of []s), | proton--protons--; also called [] number | atomic--. | |
| Arranging the elements according to their atomic number gives []g patterns in the []s of elements | repeating--properties--; each element in the periodic table is placed in a [] with those of similar properties | column |
Created by:
Toluo
Popular Chemistry sets