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
Which one is the atomic and mass number?
Mass number on the top atomic on the bottom
How do you get the number of neutrons?
Subtract the atomic number from the mass number
What are isotopes?
Isotopes have the same atomic number but different mass numbers
How do you calculate relative atomic mass?
Sum of (isotope abundance x isotope mass number) / sum of abundance of all the isotopes
What is chromatography?
Separating dyes by writing it on a piece of paper and putting that paper in water so the water contaminates the sheet and separates the dyes
What is evaporation?
A solution is poured into an evaporating dish, it’s heated so the solvents will evaporate and the solution gets more concentrated, eventually crystals will start to form,
What is crystallization?
Pour the solution into an evaporating dish then heat the solution and some of the solvent will evaporate so the solution will get more concentrated. When the solution has evaporated or when crystals start to form, let the dish cool down, the salt should start to form crystals as it becomes insoluble in the cold, filter the crystals out and put them in a warm place (drying oven)
What is the plum pudding model?
It shows the atom as a ball of positive charge with electrons stuck in it
How do acids and bases neutralize each other?
Acid + base = salt + water
H+ + OH- = H2O
Aqueous
