C1- Atomic structure and the periodic table Flashcards
Define isotope
Different forms of the same element which have the same number of protons but a different number of neutrons.
Define element
An element is a substance made up of atoms that all have the same number of protons in their nucleus.
To find the number of neutrons in an atom you?
Subtract the atomic number from the mass number.
Which number is the mass number and what does it tell you?
The top number
It tells you the total number of protons and neutrons in the atom.
Which number is the atomic number and what does it tell you?
The bottom number
It tells you the number of protons.
What is an ion?
An atom or group of atoms that has lost or gained electrons.
Why do ions have an overall charge?
The number of protons do not equal the number of electrons.
Why do atoms not have an overall charge?
They have the same number of protons and electrons so the charges cancel out
Number of protons in an atom is equal to?
The number of electrons.
The volume of the whats orbit determines the size of the atom?
Electrons
Electrons move around the nucleus in?
Shells
State the relative mass of protons, neutrons and electrons
Protons= 1
Neutrons= 1
Electrons= Almost 0
State the charge of protons, neutrons and electrons
Protons= +1
Neutrons= 0
Electrons= -1
Where is most of the mass of the atom concentrated?
The nucleus
What is the radius of the nucleus?
1x10^-14m
What is the overall charge of the nucleus?
Protons + Neutrons = Positive charge
What is the radius of the atom?
0.1 nanometres
(1x10^-10m)
Isotopes have the same ________ number but different _______ numbers.
Atomic
Mass
How are compounds formed?
When elements react atoms combine with other atoms to from compounds.
Define Compound
Substances formed by two or more elements, the atoms of each are in fixed proportions throughout the compound and they’re held together by chemical bonds.
What happens when a bond is made?
Involves giving atoms away and taking or sharing electrons.
How can you serrate the original elements of a compound?
Through a chemical reaction.
What is an ionic compound formed from?
One formed from a metal and a non metal.
The metal ion in the compound ______ electrons to form______ ions and the non metal does the opposite.
Loses
Positive
What is ionic bonding?
The opposite charges of the ions causes a strong attraction.
What does a compound made of non metals consist of?
Molecules
What type of bonding is in a molecular compound?
Covalent bonding
What is covalent bonding?
An atom sharing an electron with another atom
Properties of a compound are different or the same as the original elements
Usually completely different
What shows the elements in a compound
A formula such as CO2
Define nucleus
Contains protons and neutrons and nearly the whole mass of the atom is concentrated in the nucleus.
What is a mixture?
Elements or compounds with no chemical bond between them, that can be separated using physical methods. It does not form new substances.
List 5 physical methods of separating mixtures
Filtration
Crystallisation
Simple distillation
Fractional distillation
Chromatography
How did John Dalton describe atoms?
Solid spheres of different elements
How did JJ Thompson describe atoms?
Plum pudding model
Ball of positive charge with negatively charged electrons embedded in it
How did Ernest Rutherford describe atoms?
Nuclear model
A tiny positively charged nucleus at the centre where the mass is concentrated. A cloud of negative electrons surround the nucleus. It is mostly empty space.
Why was Rutherford wrong?
The cloud of negative electrons would be attracted and the atom would collapse.
How did Neil’s Bohr describe atoms?
Electrons orbit in shells at a fixed distance from the nucleus.
Who discovered protons?
Rutherford
Who discovered neutrons?
James Chadwick
What was the order of discovery of parts of the atom?
Atom
Electrons
Nucleus
Protons
Neutrons
What was the order of people atom discovery?
Leviticus
John Dalton
JJ Thompson
Ernest Rutherford
Neil’s Bohr
James Chadwick
How do you know the electronic structure of an element?
Atomic number = protons
Protons = electrons
How was the periodic table arranged in early 1800s?
Their physical and chemical properties
Their relative atomic mass
What is relative atomic mass?
The average mass of one atom of an element
Who left gaps and predicted elements in the periodic table?
Dmitri Mendeleev
When did Dmitri make his table?
1869
How did Mendeleev order his table?
Mostly in order of atomic mass but switched order if elements had similar properties.
How is the modern periodic table arranged?
Increasing atomic (proton) number
Which side are metals found?
Left
What does the group number tell you?
The number of electrons in the outer shell
Properties of metals
Strong
Malleable
Good conductors of heat and electricity
High boiling points and melting points
Why are metals more likely to form positive ions when they react?
They don’t have many electrons to lose and they need less energy to lose electrons as they have a weaker attraction.
Properties of non metals
Dull looking and brittle
Some are not solids at room temperature
Don’t conduct electricity They often have a lower density
What are transition metals?
Typical metals with some additional properties
What are the properties of transition metals?
Can have more than one ion
Often coloured metal ions
Good catalysts
Properties of group 1 elements
Very reactive
Soft
Low density
Alkali metals
What is the trend of alkali metals as you go down group one?
Increasing reactivity
Lower melting point
Lower boiling point
Higher relative atomic mass
What do alkali metals and non metals form?
Ionic compounds
How do group 1 metals react with water?
React vigorously to produce hydrogen gas and metal hydroxides, compounds that dissolve in water to produce alkaline solutions
How does potassium react with water?
Ignites hydrogen
How do group 1 metals react with chlorine?
React vigorously when heated in chlorine gas to form white metal chloride salts
How do group 1 metals react with oxygen?
React to form a metal oxide
Lithium forms lithium oxide
Sodium forms a mixture of sodium oxide and peroxide
Potassium reacts to form a mixture of potassium peroxide and superoxide
What are the properties of group 7 elements?
Halogens
Non metals
Coloured vapours
Molecules or pairs of atoms
Properties of fluorine
Very reactive
Poisonous
Yellow
Gas
Properties of chlorine
Fairly reactive
Poisonous
Dense
Green
Gas
Properties of bromine
Dense
Poisonous
Red brown
Volatile
Liquid
Properties of iodine
Dark grey
Crystalline
Solid
OR
Purple
Vapour
What happens when you go down group 7?
The halogens become less reactive
Have higher melting and boiling points
Have higher relative atomic masses
What do halogens and non metals form?
Molecular compounds
Simple molecular structures
What do halogens and metals form?
Ionic bonds
Ionic structured compounds
When does a displacement reaction occur?
Between a more reactive halogen and the salt of a less reactive one
Properties of group 0 elements
Noble gases
Inert
Colourless at room temperature
Full outer shell
Monatomic gases or single atoms not bonded to each other
Non flammable
What happens to group 0 elements as you go down the table?
The boiling points increase
The relative atomic masses increase
