C1 - Atomic Structure Flashcards
The history of the periodic table
True or false: Dalton was the earliest contributor to the periodic table and published a list of elements
True
The history of the periodic table
What were Dobereiners triads?
Elements with similar chemical properties that were in groups of three
For example: lithium sodium and potassium due to similar reactions with water
The history of the periodic table
How did Newlands arrange the periodic table?
Arranged elements in and sort every eighth element reacts in a similar way
The history of the periodic table
What did Newlands call the fact that every eighth element in his table reacted the same way?
Law of Octaves
The history of the periodic table
True or false, both Newlands and Dobereiners collected, lithium, sodium, and potassium together
True
The history of the periodic table
What was the problem with the law of octaves?
 Some elements were grouped which had completely different properties (this was because they were ordered only increasing atomic weight)
The history of the periodic table
How did Dmitri Mendeleyev order the periodic table?
Give three things that he did correctly
He switched the order of elements to fit patterns of chemical properties already in the table.
He arranged elements in increasing atomic weight.
He also left gaps in the periodic table.
The history of the periodic table
Why did Dmitri Mendeleyev leave gaps in his periodic table?
He predicted the properties of elements in the gaps through their position on the table. This was good as these elements were later discovered to be correct by modern scientists. This is the main reason why his table is accepted today.
The history of the periodic table
What were the two problems with Dmitri Mendeleev’s periodic table
Protons had not been discovered yet, so he ordered elements by atomic weight, which meant due to the presence of isotopes he put some elements in the wrong order
he didn’t have noble gases.
The history of the periodic table
How do we arrange the periodic table now?
give three details
We arrange periodic table by increasing number of protons (atomic number).
We have groups.
We have periods.
Atoms
What is an atom?
The simplest form of matter in chemistry
Atoms
What three subatomic particles in an atom made of, and what are their charges masses and place in the atom
Proton neutron electron
+1, 0, -1
One, one, zero
Nucleus, nucleus, electron shells
Atoms
In what order are electron shells filled and how many electrons fill each shell?
Lowest to highest energy state
2, 8, 8
Atoms
What is a compound
A substance of two or more different elements, chemically bonded
Atoms
What is an element?
A pure substance made from one type of atom
Atoms
What does the group number represent in the periodic table?
The number of electrons in the outer shell
Atoms
Which way do groups go from top to bottom?
Up down
Atoms
What does the period number represent in the periodic table?
The number of electron shells
Atoms
True or false elements in the same period have similar chemical properties
True
Atoms
as you increase period number, what also increases
Reactivity
Atoms
Are periods, rows or columns
Rows
Atoms
What is the mass number represent in the periodic table
Protons, plus neutrons
Atoms
What is the atomic number represent in the periodic table?
Number of protons, all the number of electrons
Atoms
How many elements are there?
110
Atoms
Elements are arranged in increasing _____
Atomic number
Atoms
Do elements have an overall charge
No
Atoms
What is a mixture?
Two or more different substances not chemically bonded together that can be separated by physical process
History of the atomic model
Who is the author of the plum pudding model?
Thompson (1897)
History of the atomic model
What does the plum pudding model Describe?
A cloud of positive charge with negative electrons in embedded within
The negative electrons, the plums in the positive pudding
History of the atomic model
Did Thomsons model include the electron?
Yes
History of the atomic model
Did Thomsons model predict that the atom was solid?
No
History of the atomic model
Who was the author of the nuclear model?
Rutherford
History of the atomic model
What was Rutherford’s experiment in 1909?
He fired alpha particles at a very thin (a few atoms thick) piece of gold foil suspended in a vacuum
Some particles were deflected by large angles and some went straight through the foil and some were deflected 180 degrees
Deflection showed positive nucleus
Most straight through = mostly empty space
Small number coming straight back = centre of mass (nucleus) is in nucleus and the nucleus is very small!
History of the atomic model
What did Niels Bohr contribute to the model of the atom?
In 1915 he describes the fact that electrons orbit the nucleus at specific distances - in electron shells
History of the atomic model
Who discovered the modern nuclear model?
Chadwick in the 1920s
History of the atomic model
What did James Chadwick prove?
The existence of neutrons
History of the atomic model
What was the earliest of the atom and who authored it?
The bowling ball model, which proposed that the atom was a solid indivisible sphere
Dalton 1803
Isotopes
What is an isotope?
Atoms of the same element, but a different number of neutrons
Isotopes
What are the similarities and differences between two isotopes?
Proton/electron number/atomic number is the same
Number of neutrons is different
Remember in an exam always to give the number of neutrons in an isotope and name it using the full symbol (periodic symbol + mass number + atomic number)
Isotopes
What is relative atomic mass?
The average value that takes account of the abundance of isotopes of an element
Isotopes
How do you calculate relative atomic mass?
The sum of isotope abundances times isotopes mass number divided by the sum of the isotope abundances
Abundance is given as a percentage or ratio
Separating methods
What is distillation used for
Separating a mixture of two or more different liquids which have two or more different boiling points (fractional)
Of separating a liquid from a solution with a solid solute in it
Separating methods
What is the difference between fractional distillation and simple distillation?
Fractional distillation separates multiple (more than or equal to 2) different liquids with multiple (more than or equal to 2) different boiling points
Whereas simple distillation separate a solvent from a solute in a solution
Separating methods
Briefly describe the process of distillation
Heat, a mixture of solvents.
One will evaporate off into a Liebig condenser leaving behind the other solvent
This condenser cools the solvent and it drips into the conical flask
Separating methods
What is crystallisation?
The separation of a solute from a solvent to form crystals
Separating methods
Briefly describe the process of crystallisation
Evaporate the solution into a smaller volume and let it cool
As the solution cools crystals will form which can be obtained by filtration
Separating methods
What does filtration separate?
An insoluble solid from a liquid
Separating methods
Briefly describe the process of filtration
A mixture of solid and liquid or poured into the filter funnel and liquid drips through the filter paper, but solid particles are caught by the paper and separated
Separating methods
What does chromatography separate?
Mixtures of coloured compounds
Usually pen ink or food colouring agents
Separating methods
Briefly describe the process of chromatography
Spots of ink are placed on a pencil line. Paper is lowered into water below the pencil line and dye spreads up the paper.
Ink is separated into its colours forming a chromatogram.
Separating methods
What is a paper with separated chromatography inks called?
A chromatogram
Separating methods
The further up the paper a colour travels the more soluble/insoluble it is
Soluble
Separating methods
How could you increase the accuracy of a chromatography experiment?
 Put a lid on the beaker, prevent the liquid evaporating off
If it did not have a lid this would give the wrong RF value as the solvent wouldn’t travel high up enough the page
Separating methods
What is an RF value and how is it calculated?
It’s called the retardation factor
It is calculated by the distance, moved by the compound divided by the distance moved by the solvent
In this case, it’s the distance moved by the colour divided by the distance moved by water
Separating mixtures
What is a solution?
When is solute is dissolved in a solvent
Separating mixtures
What is a solvent?
A liquid substance, which may be mixed with a solute to make a solution
Separating mixtures
What does insoluble mean?
The solute can’t be dissolved in a solvent
Separating mixtures
What is a solute?
A solid substance which may be dissolved into the solvent to form a solution
Separating mixtures
What does soluble mean?
A solute that can dissolve with a solvent
Separating mixtures
What is a mixture?
Different substances, not chemically joined 
Why did Rutherford do his experiment in a vacuum?
So that any deflections were due to the gold foil and nothing else
Why was gold used by Rutherford in his experiments on the atom?
It was the only metal that could be rolled out very thin without cracking
Give all the diatomic elements and a way to remember them
Hydrogen
Nitrogen
Fluorine
Oxygen
Iodine
Chlorine
Bromine
Have no fear of ice cold beer!
True or false: elements in a compound are in fixed proportions
True
What is the chemical formula for magnesium oxide?
MgO
What is the chemical formula of sodium chloride
NaCl
What is the chemical formula of potassium bromide?
KBr
What is the formula for magnesium iodide?
MgI2
What is the formula for carbon monoxide?
CO
What is the Cornu,a for sulfur trioxide?
SO3
What is the formula for ammonia?
NH3
What is the formula for methane>
CH4
What is an ion?
A charged particle formed when an atom loses or gains electrons
What is the formula of a sodium ion?
Na+
What is the formula of a magnesium ion?
Mg2+
What is the formula of a chloride ion?
Cl-
Remember it is CHLORIDE when an ion and only chlorine as a normal element diatomic
What is the formula of an oxygen ion?
O2-
What is the formula of sodium oxide?
NaO2
What is the formula of magnesium chloride?
MgCl2
What does the state symbol (aq) mean?
Aqueous solution
What is the law of the conservation of mass?
No atoms are lost or made during a chemical reaction
(Total mass of products = total mass of reactants)
What is an element?
A substance made up of one atom only
What is a molecule?
A collection of two or more atoms held together by chemical bonds
Bitesize
What is filtration used to separate?
Separates an insoluble solid from a liquid
Bitesize
Give two examples where filtration is useful
Mix of sand and water
Excess reactant from mixture
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How does filtration paper work?
It has tiny pores which let small molecules through but not larger in dissolved particles
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Give 3 pieces of equipment needed for filtration
Filter paper
Filter funnel
Beakers
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What does crystallisation produce?
Solid crystals from a solution
Bitesize
Give an example of what crystallisation is used for:
Getting copper sulfate crystals from a copper sulfate solution
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Give 3 bits of equipment needed for crystallisation
Evaporating basin
Bunsen burner
Tripod
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Describe the process of crystallisation:
Heat evaporates most of solvent
Leave the rest to evaporate over time leaving larger crystals
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How do you make big crystals?
Heat over a boiling water bath instead of
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What is simple distillation?
Separation of a solvent from a solution
Bitesize
Give an example of something simple distillation is useful for
Producing pure water from seawater
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How does simple distillation work?
The dissolved solute has a much higher boiling point than the solvent
So when heated only the solvent vaporises off and can be moved away
Bitesize
Give 4 pieces of equipment needed for simple distillation
Leibig condenser/condensing tube
Beaker
Bunsen burner
Conical flask with bung
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What is fractional distillation?
Separated different liquids from a mixture of liquids
Bitesize g
Give 2 examples of uses of fractional distillation
Separating ethanol from ethanol and water mixture
Separating fractions from crude oil
Bitesize
Describe the process of fractional distillation:
Gas rises through a column which has a temperature gradient (cooler at top, hotter at bottom)
Gas condenses when reaches boiling point
Liquids led away from the column
Bitesize
Why does fractional distillation work - in what circumstances would it not work?
Liquids have different boiling points
If they had the same/very very similar boiling points
Bitesize
What is the column with the temperature gradient used in fractional distillation also called?
Fractionating column
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What is paper chromatography used to separate?
Mixtures of soluble substances
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Give 4 pieces of equipment for chromatography:
Pencil, inks, water, beaker
Bitesize
What are the two phases of chromatography?
Stationary phase and mobile phase
Stationary phase = the uniform, absorbent paper
Mobile phase = solvent that moves through paper (usually water) carry substances
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Why do different substances move at different speeds through the paper?
They are more/less soluble
Or they are more/less attracted to the stationary/mobile phase
(Latter is unnecessary likely)
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What is a chromatogram?
The results of separating mixtures by chromatography
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How do you spot the difference between a pure and impure substance on a chromatogram?
A pure substance has 1 spot on chromatogram
A mixture/impure produces 2 or more
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Give 3 ways of checking if two substances are the same:
They travel same distance up paper (same Rf value)
They have same number of spots
Their spots are the same colour
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When did Dalton say his thing and what did he say?
1803 - he said matter was made up of tiny indivisible spheres called atoms
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Who came up with the plum pudding model of the atom?
What did he discover which led him to it?
JJ Thompson
The electron
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Give 3 conclusions Rutherford made from his experiment:
Mass of atom in nucleus
Nucleus has positive charge
Mostly empty space
Bitesize
Give the name of Rutherford’s model
The nuclear model
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Give the order in which these things were discovered:
Proton
Electron
Neutron
Nucleus
Electron shells
Electron
Nucleus
Electron shells
Proton
Neutron
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What is the radius of an atom?
1 x 10 to the power -10 m
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What is the radius of a nucleus compared to the radius of an atom?
More than 10 000 times smaller
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What is the radius of a nucleus?
1 x 10 to the power -14 m
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What property is unique across every element - and will always tell you the type of element you have
Number of protons
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An element has equal numbers of what?
Protons and electrons
(Sometimes they say an atom does too? I would stick with element)
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Give the 3 isotopes of hydrogen and state which is most common
H1 H2 and H3
H1
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Number of what determines chemical properties:
Electrons
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What are chemical properties?
How a substance reacts with another
Substance
(Flammability, pH etc)
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What is relative atomic mass?
The average of all the masses of isotopes of an element (taking their abundance into account )
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True or false mass number = relative atomic mass
Which one is found on the periodic table?
False
Relative atomic mass
(Mass number is always a whole number, but relative atomic mass is usually rounded)
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Which atom is relative atomic mass based off?
1/12th of the mass of a carbon 12 atom
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What is relative atomic mass?
Mean relative mass of the different isotopes of an element
Number of times heavier an atom is compared to 1/12th of the mass of a carbon atom
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What measure did early scientists use to order the periodic table?
Atomic weight (relative atomic mass)
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Give 2 issues with early periodic tables:
They were incomplete and some elements were placed in the wrong groups (with elements not similar to them)
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Why did Mendeleev leave gaps in his table?
He knew an element should be in the gap but it hadn’t been discovered yet
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What did leaving gaps allow Mendeleev to do? Give an example:
Predict the properties of the missing elements
He predicted ‘eka-silicon’ would go below silicon - and later germanium was discovered to fit the position!
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What did Mendeleev do with his periodic table to make it better? Give en example
He swapped elements to make them fit with other elements with similar chemical properties even if their atomic weight put them somewhere else in the table
Eg he swapped iodine and tellurium to make iodine linked with chlorine and bromine
Bitesize
The existence of what explains pair reversals
Isotopes (basically atomic weight/relative atomic mass is the wrong way to order your periodic table)
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What is electronic structure
The way electrons are arranged
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What type of ions do metals become when reacted?
Positive ions
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What happens when magnesium burns in air?
It loses 2 electrons becoming an Mg2+ ion
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True or false: most metal oxides are basic?
True
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True or false: most non-metal oxides are acidic
True
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Which of the two tends to have high boiling points?
Non metals
Metals
Metals (obvs)
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Give 8 properties of a metal when solid:
Brittle
Ductile
Malleable
Sonorous
Good conductor of electricity
Good conductor of heat
Shiny
High density
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Give 6 properties of a typical non-metal
Dull
Brittle
Poor conductor (of heat + electricity)
Low density
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Elements in group 1 + 2 are….
Metals
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How many electrons do elements in group 2 have in their outer shell?
2
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Give the 3 group numbers of non metals
6,7,0
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Give the name for group 0
Noble gases
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What do noble gases exist as?
Single atoms
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Are the boiling points of noble gases high or low?
Low
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What element has the lowest overall boiling point?
Helium
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What is the trend in boiling points going down group 0? Why?
Increase
Larger atoms
More intermolecular force between atoms/becomes stronger
More energy is needed to overcome these forces
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What word describes how Unreactive group 0 are?
Inert
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The noble gases have complete outer..
Shells
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Give the name of group 1
The alkali metals
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Give 3 properties of metals in group 1
Soft (can be cut with knife)
Low melting point
Low density
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How does melting point change down group 1?
Melting point decreases down group 1
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True or false:ions have a stable electron arrangement
True
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When alkali metals react with water what do they produce?
A metal hydroxide and hydrogen
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What is an alkali?
A base that is soluble in water (dissolves in water to form an alkaline solution)
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What is a base
A substance that reacts with an acid to neutralise it and produce a salt
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What happens to the reactivity of metals down group 1?
It increases
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What do group 1 elements make when exposed to air
Metal oxides
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What is the colour of the surface which is made when oxygen reacts with a metal?
White
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Reaction with chlorine t make a metal chloride gets more or less vigorous down group 1
More
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Why does reactivity increase down group 1?
Atom is larger
Outer electron further from nucleus
Force of attraction between nucleus and outer electron decreases
Outer electron lost more easily
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What are group 7 elements called?
Halogens
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Halogens exist as simple ___
Molecules
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What type of bond are halogens joined by?
Single covalent bond
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Down group 7 _____ increases
Relative molecular mass
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Further down group 7 the ___ point increases/decreases
Increases
(As larger atoms
stronger intermolecular forces
More energy needed to overcome them)
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When halogens react with metals what do they produce?
Salts
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The reactivity in group 7 increases/decreases down the group
Decreases
(As harder to gain as less attractive force to nucleus as further away from nucleus)
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When a halogen reacts with non metals what is formed?
Hydrogen halide
Hydrogen + chlorine -> hydrogen chloride
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Hydrogen halides are ___ at room temperature
Gases
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What do hydrogen halides dissolve in water to produce?
Acidic solutions
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Give an example of a hydrogen halide dissolving in water to form an acid
HCl dissolves to form Hydrochloric acid
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A more reactive halogen will ___ a less reactive halogen from solutions
Displace
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If iodine solution forms the reaction mixture turns darker or lighter?
Darker
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Explain why reactivity decreases down group 7
Atoms become larger
Outer shell further from the nucleus
Force of attraction between nucleus and outer shell decreases
Outer electron gained less easily
Halogen becomes less reactive
Bitesize
Give 4 ways in which transition metals are different from other metals
High melt points
Higher density
Greater strength
Greater hardness
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Give 6 elements that are typical transition metals
Chromium
Manganese
Iron
Cobalt
Nickel
Copper
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True or false: transition metals aren’t very reactive with oxygen at room temperature
True
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Do transition metals react very vigorously with water at room temperature? Give an example of an element that does
No
Iron - to form hydrated iron oxide (rust)_
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True or false: transition metals always have one specific ionic charge
False - they will often make different charges such as copper which can be Cu 1 2 or 3
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True or false: transition metals form white compounds
False: they form coloured compounds
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Iron is the catalyst in what process which makes ammonia
Haber process
(Reacts nitrogen and oxygen)
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Describe how copper chloride crystals could be made from copper carbonate and dilute Hydrochloric acid
Add excess copper carbonate to dilute Hydrochloric acid
Filter
Heat filtrate to evaporate some water leave to cool
N