EXAM Flashcards
What is Chemistry?
The study of the structure and properties of different substances.
Who is a chemist?
A person who studies Chemistry
What is a chemical reaction?
When substances react together, they undergo a chemical change and form completely new substances.
How do we represent a chemical reaction?
Using a chemical equation or a word equation.
What is the arrangement of a solid?
Tightly packed in a regular arrangement.
What is the arrangement of a liquid?
Particles are close together and in an irregular arrangement.
What is the arrangement of a gas?
Particles are far apart and irregular.
How do atoms in a solid move?
They vibrate in fixed positions.
How do atoms in a liquid move?
They move over each other.
How do particles in a gas move?
They move freely and faster.
What’s the volume of a solid?
Fixed Volume.
What’s the volume of a liquid?
Fixed Liquid.
What’s the volume of a gas?
No fixed volume.
What’s the shape of a solid?
Definite shape.
What’s the shape of a liquid?
No fixed shape and takes the shape of the container.
What’s the shape of a gas?
No fixed shape and spread throughout the container.
What’s the compressibility of a solid?
Cannot be compressed.
What’s the force of attraction of solids?
Strong forces of attraction.
What’s the force of attraction for liquids?
Weaker forces of attraction.
What’s the force of attraction of gases?
No forces of attraction.
What’s the energy of solids?
Lower kinetic energy.
What’s the energy of liquids?
More energy than solids but less that gases.
What’s the energy for gases?
Greatest kinetic energy.
What’s solid to liquid?
Melting
What’s liquid to gas?
Vaporization.
What’s gas to liquid?
Condensation.
What’s liquid to solid?
Freezing.
What’s Solid to Gas?
Sublimation.
What’s gas to solid?
Reverse sublimation.
What’s the difference between boiling and evaporation?
Boiling happens at the boiling point only. At this temperature, all particles are able to convert from liquid to gas.
Evaporation happens over a range of temperatures and is a surface phenonomenon.
What is the Diffusion?
When particles move from a place of high concentration to a place of low concentration till the particles are evenly spread out.
In what substances does diffusion take place?
Liquids and Gases.
What is an element?
A substance containing only one type of atom.
What is a compound?
A chemical substance consisted of two or more elements chemically-bonded together.
What is a mixture?
Two or more substances that are physically mixed with each other and can be easily separated are called mixtures.
A compound is formed as a result of a…
Chemical Reaction.
The properties of a. compound are unique, therefore it is independant of the reactions.
What is a solute?
A soluble solid dissolved in a solvent.
What is a solvent?
A liquid that dissolves a solute.
What is a solution?
When a solute is dissolved in a solvent.
What is insoluble?
When a solute does not dissolve in a solvent.
what is partially soluble?
When a solute partly dissolves into the solvent.
What is a suspension?
A mixture formed when a substance is partially soluble in the solvent, so it forms a solution which is cloudy, this is called a suspension solution.
What happens during dissolving?
There are spaces between solvent particles. Solute particles go in between solvent particles when dissolving. Mass is conserved when dissolving.
What is a saturated solution?
A saturated solution is a solution that has the maximum amount of solute dissolved in it at a specific temperature.
A solution in which no more solid can dissolve in it.
What is an atom?
The basica building block of matter.
What is a molucule?
2 or more atoms that are chemically bonded.
What is an ion?
Ions are charged particles, when atoms gain/lose a charge.
Why are atoms neutral?
Because an atom contains equal numbers of protons (positive charges) and electron (negative charges).
During a chemical reaction, an ion…
may gain or lose electrons.
What is a ANION?
If an atom gains an electron, it becomes a ANION. (negative charged ion).
What is an Cation
If an atom loses electron, it becomes a Cation (positive charged ion).
What is filtration?
This is the method used to separate an insoluble solid from a liquid.
Draw a diagram for a Filtration set up?
Filter paper,
Funnel,
Bung,
Residue,
Salt Walter,
Conical flask,
Beaker containing mixture.
What is separation using a separating funnel?
separating a immiscible liquid from a mixture of other liquids.
Draw a diagram for separating using a separation funnel.
Separating Funnel,
tap,
oil,
funnel
What is decanting?
Separating a liquid from an insoluble solid
What is separating using a magnet?
Separating a ferromagnetic substance from a mixture with non-ferromagnetic material.
What is simple dilstillation?
separating a liquid from a solution.
Draw a diagram for simple distillation
thermometer; heat, solution, round bottom-flask; water cooled condenser, water in, water out, pure solvent, beaker.
What is fractional distillation?
Separating a miscible liquid from a mixture with other liquids.
Draw a diagram for fractional distillation:
THERMOMETER;
HEAT,
ROUND BOTTOMED FLASK
MIXTURE OF LIQUIDS
FRACTIONING COLUMN,
WATER COOLED CONDENSER,
WATER IN,
WATER OUT,
ONE PURE LIQUID,
BEAKER
What is crystyllization?
Separating a soluble solid from a solution
(ex sodium chloride from water)
Why is crystallization significatn?
It is both a purification and separation technique.
What is chromatography?
Separating a mixture of dyes from each other.
Draw a chrotomahgraph?
rod holding paper,
chromatography paper,
beaker,
pencil line,
solvent
How do we analyze a chromatogram run?
The dye that travelled the furthest is the most soluble in water and the dye that travelled the least far is the least soluble in water.
What is the first group in the Periodic table called?
Alkali metals.
What is the second group in the Periodic table called?
Alkaline Earth Metals.
What is the 7th Group in the periodic table called?
Halogens.
What is the 8th group in the Periodic table called?
Noble Gases.
Horizontal rows in the periodic table are:
Periods
Verical columns in the periodic table are called
Groups
Why do elements in the same group have simillar chemical properties?
Because elements in the same group have the same amount in electrons in the last shell, causing them to have simillar properties.
Why are group 8 elements called noble gases?
They’re completely unreactive.
Draw an atom:
Nucleus,
Protons and Neutrons in the Nucleus,
Electrons in orbitals.
Why is an atom neutral by charge?
Because it has an equal amount of protons and electrons.
What is the atomic nummber?
It states how many protons an element has.
What’s the mass number?
States the mass of the element.
What are the subatomic particles in an atom:
Electrons, Protons, Neutrons.
What does the number of shells tell us about the positioning of an element on the periodic table?
It tells us the PERIOD.
What does the valency electron tell us about the positioning of the element on the periodic table?
It tells us the GROUP it belongs to.
How are elements in a periodic table arranged?
in increasing atomic number.
What is electronic configuration?
The arrangement of electrons around the nucleus.
What is the valence electron?
The number of electrons in the outer shell.
Which side of the table are metals found?
METALS are found to the LEFT,
NONMETALS are found to the RIGHT.
Some of the non-metals are in…
gasous form.
What are diatomic particles?
Elements consisting of two atoms chemically bonded together.
Examples of diatomic particles?
F2, CL2, BR2, I2, N2, O2
What are the items on the left side of the chemical equation called?
Reactants
What are the items on the right side of the chemical equation called?
Products.
Explain why products formed in chemical reactions will have different chemical properties to that of the reactants in terms of electrons.
During a chemical reaction, there will be a transference of electrons or sharing electrons. Therefore, the product formed will have different chemical properties to that of the reactant.
12
C
6
What does the top number mean?
Protons + Neutrons.
What does the second number mean?
12
C
6
Number of protons.
WHAT DOES THIS NUMBER MEAN?
12
C +3
6
This means that 3 electrons have been subtracted. So the number of electrons will be 3.
