Chemistry, Autumn 2022 Flashcards
What is located in the centre of the atom?
Nucleus
What surrounds the nucleus?
Electrons arranged in shells
What makes up the nucleus?
Protons and neutrons
What is the relative atomic mass/ram?
The number of protons and neutrons
What is the atomic number on the periodic table?
Number of protons or electrons
What is the mass number on the periodic table?
Relative atomic mass
What is the charge of a proton?
Positive
What is the charge of a neutron?
Neutral
What is the charge of an electron?
Negative
Where are the transition metals on the periodic table?
Between group 2 and 3
Do transition metals have a low or high melting point?
High melting point
How dense are transition metals?
High density
What can transition metals and their compounds act as?
Catalysts
How do catalysts affect the rate of reaction?
They speed it up without being used up in the reaction
What is ionic bonding?
When atoms lose/gain electrons to gain a full outer shell
What is the structure of an ionic bond?
Regular structure, alternating positive and negatives ions and giant ionic lattice.
Why are ionic bonds crystalline and solid at room temperature?
Because of its regular structure of alternating positive and negative ions
Why do ionic bonds have a high melting/boiling point?
Because there is a strong electrostatic force of attraction between positive and negative ions
When do ionic bonds conduct electricity and why?
When they’re molten/dissolved because ions are free to move
What is covalent bonding?
Atoms share electrons
Why is a simple covalent bond liquid or gas at room temp?
Because of the low boiling point caused by intermolecular forces that are easy to be overcome by heat.
What is the structure of a simple covalent bond?
Simple molecular and small molecules
What is the structure of a graphite covalent bond?
Giant covalent structure, layered and weak intermolecular forces holding the layers together.
Why do graphite covalent bond conduct electricity?
Because one electron per atom is free to move and can carry electric charge.
What is metallic bonding?
A lattice of positive ions surrounded by a sea of delocalised electrons.
What is the structure of a metallic bond?
Layers of positive ions, in a sea of free electrons and a giant metallic structure
What does malleable mean?
Can be hammered into shape
What does ductile mean?
Can be drawn into wires
Why are metallic bonds malleable and ductile?
Because it has layers that slide
Why are metallic bonds strong and have a high melting point?
Because of the electrostatic attraction holding the structure together.
Why do metallic bonds conduct heat and electricity?
Because the outer electrons are free to move and carry electrical charge.
What is an ion?
An atom or molecule with charge
Loss of electrons is…
positive
Gain of electrons is…
negative
What are electrolytes?
Ionic compounds that are in a molten state or dissolved in water so ions are free to move
What is electrolysis?
Electrolysis is the decomposition of an electrolyte by an electric current. It is used to extract reactive metals from their ores.
What is the charge of a cation?
Positive
What is a charge of an anion?
Negative
What happens at the cathode?
At the cathode, whether the hydrogen or metal is produced there depends on the position of the metal in the reactivity series.
The metal is produced at the cathode if..
it is less reactive than hydrogen
Hydrogen is produced at the cathode if…
the metal is more reactive than hydrogen.
Metal reactivity series
Potassium, Sodium, Lithium, Calcium, Magnesium, Aluminium, Zinc, Iron, Tin, Lead, (Hydrogen), Copper, Silver, Gold
What happens at the anode?
Oxygens are produced unless halide ions are present. Then the negative halide ions lose electrons and make the corresponding halogen.
What are halide ions?
Ions of group 7
What is an endothermic reaction?
Reactions that take thermal energy from its environment to proceed
What is an exothermic reaction?
Reactions that release thermal energy
