unit 1 chemestry Flashcards
Why do noble gases dont react easily?
Because they have a full outer shell and a stable electron configuration.
What is ionic bonding?
Electrostatic attraction between two oppositely charged electrons.
What is electrostatic attraction?
The force experienced between two oppositevely charged electrons.
What holds the ionic bonding together?
Electrostatic forces which is the force experienced by two oppositevely charged particles. It holds the particles together.
What is a giant ionic lattice?
An arrangement of positive and negative Ions.
What is the strength of electrostatic forces dependant on?
The ionic charge and ionic radii of the ions.
When an atom has more electrons it will have more shells which means the radius is bigger.
Why is the force weaker if the ionic radius is bigger?
Because the ionic charge is spread over a large surface area.
What makes an atom has more of an electronegativity?M
More protons as the nucleus will attract more electrons.
What is electronegativity?
The tendancy of an atom to attract a bonding pair electrons.
What is a polar molecule?
When one of the atoms gets a bigger share of the electrons than the other.
What does a polar molecule be known for?
Know for unequal number of electrons shared.
What are the charges of the polyatomic Ions?
CO32-, SO42-,NO3-,OH-.
What does the strength of an ionic bond depend on?
It depends on the the charges and the size, the more the charge the more the force, the more the size, the weaker the force because the charges are spread out and the less the size the more the force as the ionic charges and the opposite charges are closer to each other.
What is the difference between an ion and a neutral atom?
An ion has an either overall positive or negative charge. A neutral atom has en equal number of charge.
How is a covalent bond formed?
By mutual sharing of electrons between atoms. They share an electron.
What is the bond length?
DIstance between the shared nucleus.
What affects the electronegativity of an atom?
The number of shells, more the shells the less the attraction as the nucleus is further away, more protons as the nucleus attracts more electrons so attraction is stronger. It is stronger across a period and may be weaker down a group depending on the proton pattern.
What holds metallic bonds together?
The attraction between the positive and delocalised electrons.
What are properties of the metals?
Malleaable, ductile,good conduct of heat and good conduct of electricity.
What are the two types of compounds?
Covalent and ionic.
How to find the electrons gained for the non-metals?
8-the group number and that is the number of electrons gained.
Why are metallic bonds good conduct of electricity?
Because they have negative charge and electrons which flow freely through the metal. Current is the flow of charge.
Why are metallic bonds good conduct of heat?
Because they vibrate and pass heat energy to neighbouring particles.
Why are metallic metals good conduct of malleable?
Because they have forces that allow the atoms to slide.
What does the melting point depend on metals?
Number of shells and positive and protons and the delocalised electrons in the outer shell. More the shell,weaker the melting point. More protons more melting point and more delocalised electrons means more metallic bonds.
What are the properties of london intermolecular forces?
Weak
Attraction lasts for a very short time.
The electrons around the atom are not always perfectly evenly ditributed. One side of the atom may be positive or negative.
What is a dipole force?
Very weak when the positive end of the molecule and negative end may attract for a short time.
What is a permanent dipole-dipole?
When positive end and negative end will attract all the time.
What is hydrogen bond?
When hydrogen bond with oxygen,fluorine and nitrogen and it is called a large bond.
What is the meaning of relative atomic mass?
How heavy an element is compared to the 1/12 of a carbon atom.
What is the relative molecular mass for?
Molecules
What is the relative formula mass for?
Ionic bonds
How many elements in the periodic table?
92 elements
Why are elements put in the order that they are in the periodic table?
Because They are in order of atomic mass
Meaning of ionisation energy?
Minimum amount of energy required to remove an electron.
How does ionisation energy change when you go from left right on the periodic table and why?
Ionisation energy increases because the force of attraction between the electrons and nucleus is bigger.
Why do period 3 elements have smaller ionisation energy than period 2?
Because period 3 elements have electrons which are further from the nucleus and so force of attraction is weaker.
What is electron affinity?
Energy released when an atom gains an electron.
How does atomic radius change down a group?
Increases and so more shells.
How does atomic radius change from left to right on the periodic table?
Atomic radius decreases as there is more protons and so more attraction and smaller radius.
Why does melting point decrease goring down a group?
Because atoms are bigger goring down a group and so electrostatic forces between the nuclei and free electrons is smaller.
Formula for reaction of lithium with oxygen (group 1)?
4li+02-2lismall 20
What are propoties of the non metal oxides?
Properties of the non metal oxides is that they are gases and simple molecules.
What are propoties of metal oxides?
Most are solids and giant ionic lattice and some are giant covalent lattices.
Which will give an acidic solution when dissolved in water?
Non metal oxides
Which oxide will form alkaline solutions when dissolved in water?
Metal oxides
What controls what salt we get?
The metal and the acid.
What does the Bauxite ore consist of?
Aluminimum oxide
What does the Haematite ore consist of?
Iron oxide
What does the Malachite ore consist of?
Copper carbonate
What does the reactivity series tell us?
What method is needed to extract a metal based on it reactivity.
How are the metals more reactive than carbon extracted?
By electrolysis which requires a lot of energy and so is expensive.
What happens when lithium is added to water?
It floats and then fizzes steadily and becomes smaller until it eventually disappears.
What is an alloy?
An alloy has more than one type of atom so have different shapes. They are also held together strong bonds but in less regular structres . An alloy is a mixture of two or more elements
