C1 And C2-Atomic Structure And Periodic Table Flashcards
(140 cards)
1
Q
What is an atom
A
the smallest part of an element that can still be recognised as that element
2
Q
What is an element?
A
A substance which is made up one atom and cannot be broken down.
3
Q
What are compounds
A
Compounds are two or more elements chemically combined in fixed proportions and can be represented by formulae using symbols of the atoms from which they were formed.
4
Q
How can compounds be seperated
A
Chemical reactions
5
Q
What is a mixture
A
A mixtures consists of two or more elements or compounds not chemically combined together.The chemical properties of each substance in the mixture are unchanged.
6
Q
The first development of the atom
A
John dalton-start of 19th century-atoms were described as solid spheres that could not be divided
7
Q
2nd part of history of atoms
A
JJ thomson-1897-plum pudding model-the plum pudding model suggested that the atom is a ball of
positive charge with negative electrons embedded in it.Discovery of the electrom
8
Q
3rd advancement of history of atoms
A
Ernest rutherford-1909-nuclear model-alpha scattering experiment-mass concentrated at the centre;the nucleus is charged.Most of the mass is in the nucleus.Most atoms are empty space.
9
Q
4th of history of atoms
A
Niels Bohr-1911-planetary model,electrons are in shells orbiting the nucleus.Specific distance from nucleus
10
Q
6th of history of atoms
A
James chadwick-1940-discovered that there are nuetrons in the nucleus
11
Q
How the ernest rutherford experiment worked
A
A beam of alpha paeticles projected at a gold foil,the gole foil surrounded by flourescent screen to detect alpha particles.Most of the alpha particles passed through but some were deflected by the centres of the metal atoms and a tiny bumber were repelled.Suggesting the nucleur model(the nucleus in middle with electrons in around)
12
Q
What is the atomic number
A
The number at the bottom which shows the number of protons and electrons.
13
Q
Mass number
A
The sum of the protons and nuetrons in an atom.This is the number at the top
14
Q
Isotopes
A
Atoms of the same elements with different numbers of nuetrons
15
Q
What isrelative atomic mass
A
An average value that takes account of the abundance of the isotopes of the element.
16
Q
How to calculate relative atomic mass
A
(Isotope 1 times abundance) +(isotope 2 times abundance) divided by 100
17
Q
What is the periodic table
A
an arrangement of elements in the order of their atomic numbers, forming groups and periods
18
Q
How was john new lands periodic table like
A
Ordered his table in order of atomic weight,Worked in law of octaves but this broke down
19
Q
How did dmitri mandeleevs periodic table work
A
It was ordered in order of atomic mass but not always strictly in some places he changed the order based on atomic weights.Left gaps for elements that were not discovered
20
Q
What are metals
A
Elements that react to form positive ions-found at left of periodic table
21
Q
What are non metals
A
Elements that do not form positive ions-found at right and top of periodic table
22
Q
Characteristics of alkali metals
A
They react with oxygen to create oxide,they all readt with chlorine to form a white percipitate,the reactivity increases going down the group.There melting and boiling point decreases going down the group
23
Q
How does lithium react with oxygen
A
Burns with a strongly red tinged flame and produces a white solid
24
Q
How does lithium react with water
A
Fizzes,disappears gradually
25
How does lithium react with chlorine and give equation
Burns to give white solid
Lithium+chlorine=lithium chloride
26
How does sodium react with oxygen
Strong orange flame and produces white solid
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How does sodium react with water
Fizz,melts into a ball and disappears quickly
28
How does sodium react with chlorine
Burns with a bright yellow flame,cloud of white powder and settle on the sides of the container
29
How does potassium react with oxygen
Large pieces produce lilac flame,smaller ones make solid immediately
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How does potassium react with water
Ignites with sparks and disappeaes
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How dows potassium react with chlorine
Burns to give white solid
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Characteristics of noble gases
All full electrons in outer shell,are uncreative,stable,the boiling points increase going down the group
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Characteristic of halogens
Similar reactions,react with metals to form ionic compounds (shared pair of electrons),going down the group the mass increases,melting point and boiling increase,but the reactivity goes down.
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Why does the reactivity go down for halogens going down the group?
Halogens react by gaining an electeon and as the number of shells of electrons increases going down the element with the least amount of shells is more reactive as there is less shielding compared to other elements.
35
Characteristic of transition metals
Harder and stronger,higher melting points,less reactive and dont react as vigorously with oxygen or water,form different colour solutions,good conductor of electricity,can become any positive ion like 2+ or 3+,different charges,useful as catalysts
36
Defintion of transition metal
The collection of metallic elements in the middle of the periodic table
37
What is an ion
An atom or molecule with an electric charge due to the gain or loss of electrons
38
How has the discovery of subatomic particles led to change in the model of the atom
Discovery of particles like electrons, protons, and neutrons showed that atoms had internal structure.
39
How has the Limitations of Previous Models led to change into the model of the atom.
Each model had flaws that couldn’t explain certain atomic behaviors.
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What are subatomic particles
Nuetrons,electrons,protons
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Mass of protons and nuetrons
1.67 x10^-27
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Mass of electron
9.11x10^-31
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What are valence electrons
All the electrons in the outer shells
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What is a group in the periodic table
A group of elements with similar reactivitys and chemical properties
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What is a period in the periodic table
A horizontal line of elements with atomic numbers going up each time,increasing valence electrons and changing properties
46
What is atomic weight
Atomic weight is basically atomic mass is a measure of the average mass of an atom of an element.
47
How was john daltons periodic table like
1808-John dalton
Elements arranged by atomic weight
Only 20 elements listed
(And not all were actually elements
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Advantages and disadvantages of john daltons periodic table
Advantages:early attempt to organise the elements
Disadvantages:Symbols difficult to use and identify
Most elements not yet been discovered.
49
What does periodic mean
Regurley occuring
50
explain the significance of chemical symbols used in formulae and equations.
Easy Identification: Quickly identifies different elements.
Composition: Shows which elements and proportions make up a compound.
Bonds and Reactions: Represents how elements bond and react in equations.
Universal Language: Standardized symbols allow global understanding.
51
explain why mass is conserved in
a chemical reaction.
Mass is conserved in a chemical reaction because atoms are simply rearranged, not created or destroyed. In any reaction, the total number of each type of atom in the reactants equals the total number in the products.
52
justify in detail how mass may
appear to change in a chemical reaction.
practical observations may lead to apparent changes due to gas exchange, measurement errors, physical state changes.
53
Difference between compound and a mixture
A compound is 2 elements which have been chemically bonded together and this cannot be reversed wheras a mixture is 2 elements that have been mised together and this can be reversed
54
experimental data to explain the classification of a substance as a compound or a mixture.
If your data shows a single, sharp melting or boiling point, it’s likely a compound.
If your data shows a range of temperatures, it's likely a mixture.
55
explain how the chemical properties of a mixture relate to the chemical it is made from.
The chemical properties of a mixture are determined by the substances it is made from, but the substances do not chemically combine,just physically , so each retains its own properties.
56
Why the model of the atom has changed over time
Subatomic particles were discovered,better experimental techniques,better understanding of atomic behaviours
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Subatomic particles charges
Protons=+1
Nuetrons=0
Electrons=-1
58
explain how evidence from scattering experiments changed the model of the atom.
the scattering experiments revealed that atoms are mostly empty space with a central nucleus
59
explain why we can be confident that there are no missing elements in the first 10 elements of the periodic table.
We can be confident that the first 10 elements are correct as they all go up in electron structures,have different chemical reactivitys compared to eachother and a complete atomic number sequence
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Why does chlorine not have a whole mass number
Abundance of chlorine 35 and 37 gives answer of 35.5
61
Describe how the electronic structure of metals and non metals is different
We can see for non metals they most of the time require the extra electron so the elements nearest the top of the table are higher reactive compared to lower wheras metals lose there electron to non metals to form a positive ion and there reactivity increases towards the lower of the group
62
explain in terms of electronic structure how the elements are arranged in the periodic table
We can see as the table progresses the different elements have different electronic structures as there atomic numbers and subatomic particles change depending where they are.There valence electrons also change depending if they are a metal which means they lose electrons becoming a positive ionor non metal which means they gain electron becoming negative jon
63
List the elements in group 1
Lithium,sodium,pottasium,Rubidium,caesium,francium
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What is a monotimic molecule
Consisting of one atom
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What is a diatomic molecules
Diatomic molecules are molecules that contain only two atoms bonded to one another.
66
Describe how you can show that hydrogen and metal hydroxides are made when Group 1 metals react with water.
Adding a few drops of an indicator will cause the water to turn purple or pink , showing that the solution is alkaline.
And lastly in chemical reaction equations we can see that hydrogen and hydroxide is formed.
67
Justify how Group 1 metals are stored and the safety precautions used when dealing with them
Group 1 metals are stored in oil so they do not oxidise and react with the oxygen.When dealing with group 1 metals you need to wear gloves and goggles and when reacting them you need to react them behind a screen
68
First four elements in Group 7
Flourine,chlorine,bromine,iodine,astatine,tennessine
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Difference between ionic bond and compound
Ionic bond is force that hold them together and ionic compound is everything.
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What is an ionic bond
strong electrostatic. force of attraction between these oppositely charged ions
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What is an ionic compound
Ionic compounds are formed when two atoms, one of which is a metal, interact and exchange electrons.
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What are ionic compounds held by
Ionic compounds are held by strong electrostatic forces of attraction by there oppositly charge ionic bonding.Between a metal and a non metal
73
What is a halogen displacement reaction?
A halogen displacement reaction occurs when a more reactive halogen displaces a less reactive halogen from a compound
74
How does chlorine displace pottasium bromide(equation)
chlorine + potassium bromide → potassium chloride + bromine
Cl,(aq) + 2KBr(aq). → 2KCI(aq) + Br, (aq)
Obviously fluorine, the most reactive of the halogens, will displace all of the others. However, it reacts so violently with water that you cannot carry out reactions in aqueous solutions.
75
What is an aqueous solution
aqueous solution" is a solution in which water is the solvent, such as salt dissolved in water
76
Why do halogens have similar reactions
They all have 7 electrons in the outer shell in which they have to gain 1 to then become a negative ion.They do this with ionic bonds with metals or covalent bonds with non metals
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Why is mercury not a normal transition metal
Has low melting point
78
Compounds of transition metals
Compounds of transition elements are coloured (as opposed to the mainly white compounds of the alkali metals). The colours of many minerals, rocks and gemstones are due to transition element ions. The reddish-brown colour in a rock is often due to iron(III) ions, Fe'. The blue colour of sapphires and the green of emeralds are both due to transition element ions in the structures of their crystals
79
Common compounds of transition metals
copper(II) sulfate is blue (due to its Cu+2 ions)
• nickel(Il) carbonate is pale green (due to its Ni+2ions)
chromium (III) oxide is dark green (due to its Cr'+3 ions)
• manganese(II) chloride is pale pink (due to its Mn?+2 ions)
80
justify the use of a transition metal or its compound in terms of its chemical properties.-
they are not reactive with water and oxygen so they can be used for structures due to less rust, and can also be used for catalysts
81
Relative mass of protons and nuetrons and electrons
Protons and nuetrons=1
Electrons=0
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Three differences of plum pudding model and nuclear model
Plum pudding is a ball of positive charge
Mass in nucleur model is concentrated wheras plum pudding its spread out.
Nucleur model has positive charge concentrated at nucleus wheras plum pudding its spread out
Electrons inside for plum pudding wheras nucleur has them outside
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Similarites of plum pudding and nucleur
Both have electrons,both have positive nucleus,no nuetrons
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Differences in physical changes of transition and group 1
Transition is harder,denser,high melting,group 1 has low melting points,soft,
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Differences in chemical changes of transition to group 1
Transition has low reactivity,used as catalysts,ions eith different charges wheras group 1 is very reactive,not used as catalysts and can only for a +1 ion
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Polyatomic ion for ammonium
Nh4 +
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Polyatomic ions for carbonate
Co3 2-
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Key formulas
Nh3=ammonia
Ch4=methane
Nacl=sodium chloride (salt)
Co2=carbon dioxide
H2O=water
SiO2=sand
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Hydrochloric acid
Hcl (aq)
90
Nitric
HNO3 (aq) [H] + [NO3]- nitrate
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Sulfuric
H2SO4 (aq) 2[H]+ [SO4]2- sulfate
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Phosphiric
H3PO4 3[H]+ [PO4]3- phospate
93
What is the electronic structure
a set of numbers to show the arrangement of electrons in their shells
94
Radium of atom
0.1nm (1x10-10m
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Radium of nucleus of atom
(1x10-14m)
96
How are compounds formed?
Compounds are formed from elements by chemical reactions.
97
What do chemical reactions often and always involve?
Chemical reactions always involve the formation of one or more new substances, and
often involve a detectable energy change.
98
List the first twenty elements in the periodic table
Hydrogen – H
Helium – He
Lithium – Li
Beryllium – Be
Boron – B
Carbon – C
Nitrogen – N
Oxygen – O
Fluorine – F
Neon – Ne
Sodium – Na
Magnesium – Mg
Aluminium – Al
Silicon – Si
Phosphorus – P
Sulfur – S
Chlorine – Cl
Argon – Ar
Potassium – K
Calcium – Ca
99
What happens if there is new experimental evidence?
New experimental evidence may lead to a scientific model being
changed or replaced.
100
5th part of thr history of the atom
Later experiments led to the idea that the positive charge of any nucleus could be subdivided into a whole number of smaller particles, each particle having the same amount of positive charge.
The name proton was given to these particles
101
What were the results of Rutherford’s scattering experiment?
Most alpha particles passed straight through
Some were deflected
A few were bounced straight back
102
What did the scattering experiment show about the atom?
Atoms are mostly empty space
There is a small, dense, positively charged nucleus at the centre
Electrons orbit the nucleus
103
Why in an atom they have no overall charge?
In an atom, the number of electrons is equal to the number of
protons in the nucleus. Atoms have no overall electrical charge.
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Why do atoms of different elements have different atomic numbers?
Because each element has a different number of protons, which is called its atomic number. If the number of protons changes, the atom becomes a different element.
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How does the nuclear model describe an atom?
An atom has a small, dense nucleus made of protons and neutrons, with electrons orbiting in shells. The atom is mostly empty space and is electrically neutral.
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In an atom what makes up most of the mass
The nucleus
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How small is an atom compared to objects in the physical world?
Atoms are about 1 × 10⁻¹⁰ m across. They're so small that around 100,000 atoms could fit across a human hair. The nucleus is 10,000 times smaller than the atom.
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How many electrons can go in each shell?
2-lowest
8-2nd
83rd
8-4th
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How can a electronic structure be represented?
The electronic structure of an atom can
be represented by numbers or by a diagram
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How are elements arranged in the periodic table?
The elements in the periodic table are arranged in order of atomic
(proton) number and so that elements with similar properties are in
columns, known as groups
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Why do elements in the same group have similar chemical properties?
Elements in the same group in the periodic table have the same number of electrons in their outer shell (outer electrons) and this gives them similar chemical properties
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How did scientists arrange elements before the discovery of protons,neutrons and electrons
Before the discovery of protons, neutrons and electrons, scientists attempted to classify the elements by arranging them in order of their atomic weights.
113
explain how and why the ordering of the elements has changed over time.
The way elements are ordered has changed because scientists learned more about atoms and found new elements.
Before the discovery of protons, neutrons and electrons, scientists attempted to classify the elements by arranging them in order of their atomic weights.
The early periodic tables were incomplete and some elements were placed in inappropriate groups if the strict order of atomic weights was followed.
Mendeleev overcame some of the problems by leaving gaps for elements that he thought had not been discovered and in some places changed the order based on atomic weights.
Elements with properties predicted by Mendeleev were discovered and filled the gaps. Knowledge of isotopes made it possible to explain why the order based on atomic weights was not always
correct.
114
What are typical physical properties of metals?
Good conductors of heat and electricity
Malleable and ductile
Shiny (lustrous)
High melting and boiling points
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What are typical physical properties of non-metals?
Poor conductors of heat and electricity (except graphite)
Brittle when solid
Dull-looking
Often have low melting and boiling points
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What are typical chemical properties of metals?
Lose electrons to form positive ions
React with oxygen to form basic oxides
More reactive metals react more easily with water or acids
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What are typical chemical properties of non-metals?
Gain or share electrons to form negative ions or covalent bonds
React with oxygen to form acidic oxides
118
How does atomic structure relate to whether an element is a metal or non-metal?
Metals (left side of periodic table) have few outer electrons → easy to lose
Non-metals (right side) have more outer electrons → tend to gain/share electrons
119
How does the number of electron shells affect an element’s position in the periodic table?
The number of electron shells = period number.
120
Describe the group 0 elements
The elements in Group 0 of the periodic table are called the noble
gases. They are unreactive and do not easily form molecules
because their atoms have stable arrangements of electrons. The
noble gases have eight electrons in their outer shell, except for
helium, which has only two electrons.
121
Describe the group 7 elements
The elements in Group 7 of the periodic table are known as the halogens and have similar reactions because they all have seven electrons in their outer shell. The halogens are non-metals and consist of molecules made of pairs of atoms.
122
What type of compounds do chlorine, bromine, and iodine form with metals?
They form ionic compounds. The halogen gains one electron from the metal to form a -1 ion (halide ion).
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What type of compounds do chlorine, bromine, and iodine form with non-metals?
They form covalent compounds by sharing electrons with other non-metals.
124
What type of bonding occurs when chlorine reacts with hydrogen?
Covalent bonding – each atom shares one electron → forms hydrogen chloride (HCl).
125
What are halide salts and how are they formed?
Halide salts are ionic compounds formed when halogens (Cl, Br, I) react with metals, producing compounds like KBr or NaI.
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What are thr froup 7 elements
Halogens
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What are the group 0 elements
Noble gases
128
What are the group 7 elements
Alkali metlas
129
What are the transition elements
The transition elements are metals with similar properties which are
different from those of the elements in Group 1.
130
How reactive are Group 1 metals with oxygen, water, and halogens?
Group 1 metals are much more reactive with:
Oxygen – form metal oxides quickly
Water – produce hydrogen gas and a metal hydroxide
Halogens – form white ionic salts
131
How reactive are transition metals compared to Group 1 metals?
Transition metals are less reactive – they don’t react as easily with water, oxygen, or halogens.
132
What ion charges can iron (Fe) have?
Iron can form Fe²⁺ and Fe³⁺ ions.
133
What are common uses of copper (Cu)?
Copper is used in electrical wiring (excellent conductor) and plumbing. It also forms blue compounds like copper(II) sulfate (CuSO₄).
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What coloured compounds does iron (Fe) form?
Iron(II) compounds are typically pale green
Iron(III) compounds are typically brown/orange
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What is a key use of manganese (Mn) in industry?
Manganese is used to make steel alloys and acts as a catalyst in some reactions.
136
What coloured compounds does copper form?
Copper(II) sulfate (CuSO₄) is blue.
Copper(I) oxide (Cu₂O) is red.
137
Give an example of a transition metal used as a catalyst.
Iron is used as a catalyst in the Haber process.
Manganese(IV) oxide (MnO₂) is a catalyst in the decomposition of hydrogen peroxide.
138
Chromium oxide
Cr2O3
139
What coloured compounds does cobalt (Co) form?
Cobalt(II) compounds are often blue or pink, such as cobalt(II) chloride (CoCl₂).
140
What coloured compound does manganese form?
Manganese(IV) oxide (MnO₂) is black and acts as a catalyst.
Manganese(II) sulfate is pale pink.
