Assessment C1 Revision Flashcards
Explain why electrons are shared
When an atom loses or gains electrons to form ions they’re trying to get a full outer shell which makes the atom very stable
Which groups are most likely to form ions and why?
Group 1 and 2- are metals and they lose electrons to form positive ions (cations)
Group 6 and 7- are non metals they gain electrons to form negative ions
(anions)
What is an ionic bond?
When a metal and non metal react they have oppositely charged ions which makes the strongly attracted by electrostatic forces. They have a structure called a giant ionic lattice and the ions form a closely packed regular lattice
State the properties of ionic compounds
They have a high melting and boiling point because the bonds between the ions are very strong. It takes a lot of energy to overcome this reaction. When solid they can’t conduct electricity, and dissolve easily in water allowing them to conduct electricity
What is a covalent bond?
Similar properties as an ionic bond, happens in compounds of non metals (H2O) and in non metal elements (CL2)
What are molecular substances?
Made up of molecules containing a few atoms joined together by covalent bonds. A few examples are Hydrogen, Chlorine, Oxygen and Nitrogen. Most molecular substances are gases or liquids at room temperature, as the molecules get bigger the melting and boiling points increase.
What is metallic bonding?
In metals the electrons in the outer shell are delocalised (free to move) they have electrostatic attraction between the positive metal ions and the shared negative electrons. They have a regular structure which is in rows
How do you calculate the mass of an element?
A x number of atoms that element divided by Mr of the compound x 100
What is Avogadro’s constant?
6.02 x 10 (23)
What is the formula for moles?
Top: mass
left: number of moles
Right: Mr
What is the formula of concentration.
Top: mass
Left: concentration
Right: volume
What is a base?
A substance with a PH greater than 7
What is the equation for neutralization?
Acid + base > salt + water
H+ + OH- > H2O
What are acids?
They have a PH between 1 and 6, strong acids completely ionise in water, all the particles dissociate to release H+ ions. Weak acids don’t and only release some H+ ions
What is the PH?
It’s the measure of the concentration of hydrogen ions
What is the reaction of an acid?
All metal oxides and hydroxides react with acids to form a salt + water
What is the reactivity series abbreviation method to learn?
Please Stop Lying Calling Me A Careless Zebra Instead Try Learning How Copper Saves Gold
Which metals are extracted by electrolysis?
Metals higher than carbon
What happens to the metals in a displacement reaction?
The metal ion gains electrons and the metal atom loses electrons
What happens during electrolysis?
The positive ions go towards the cathode to gain electrons (reduction)
The negative ions go towards the anode to lose electrons (oxidation)
What chemicals were released in the earths early atmosphere?
Carbon dioxide, methane and ammonia, volcanic activity also released nitrogen
What is agriculture?
When more farm animals produce more methane through their digestive processes
What is the charge of the nucleus?
Positive
How do u know the number of electrons?
The number of protons equals the number of electrons