Chemistry Flashcards
(64 cards)
How do you calculate the retention factor (Rf)?
distance travelled by sample / distance travelled by solvent
Describe a displacement reaction
Occurs when a react metal is added to a dissolved compound of a less reactive metal.
How can you find the rate of reaction?
Measure either the rate at which a reactant is used up
or
the rate at which one of the products is formed.
Describe the process of covalent bonding
Occurs when non-metals react with each other by sharing electrons.
What is a mixture?
A mixture contains more than one element or compound.
What is a compound?
Substance made from different elements bonded together.
Define an element.
A substance made from only one type of atom.
Name the following elements:
Br2
Cl2
F2
I2
N2
Bromine
Chlorine
Flourine
Iodine
Nitrogen
Name the properties and group of noble gases.
Group 18
Unreactive
Low melting/boiling point.
Monoatomic
Describe an endothermic reaction.
A reaction which takes in heat from its surrounding, the products have more energy than the reactants.
Describe an exothermic reaction.
A reaction which gives off heat to its surrounding. Products have less energy than the reactants.
Name factors affecting the rates of reaction.
Concentration
Temperature
Surface area
Catalysts
What elements are in group 1?
Alkali metals with 1 electron in outer shell.
What elements are in group 2?
Alkaline earth metals with 2 electrons in outer shell.
Name the parts of the atomic structure
Nucleus
Shells
Electrons
What is the mass number of an element?
The mass number is the number of protons and neutrons in an atom.
What is the atomic number of an element?
The number of protons in the nucleus.
How would you find the number of electrons in an element?
You would look at the number of protons.
The number of protons is the same as the number of electrons.
Why do reactions happen quicker at higher concentrations?
Because there is a greater number of particles to collide, making for more successful collisions.
What is a catalyst?
It is a substance that affects the rate of reaction without being used up in the reaction itself.
What are bond energies
Bond energies are a measure of the average bond strength for a particular covalent bond.
Describe the process of electrolysis
The process where a molten ionic substance is decomposed by an electrical current.
What are the relative atomic masses and charges of subatomic particles?
Protons 1 mass / +1 charge
Neutrons 1 mass / 0 charge
Electrons negligible / -1 charge
What are some properties of giant covalent bonds?
High melting/boiling point
Graphite conducts electricity
diamond and silicon is very hard.