Negative charge. -1.                        •electrons move on electron shells. 

Same numbers of protons & electrons with opposite charges cancel eachother out. 

Substance made up from atoms that have the same number of protons. 

Different forms of the same element with different number of NEUTRONS. 

 (isotope abundance x isotope  mass number).                                                       ——————————————————Sun if abundance of all isotopes. 

Atoms of elements combine together to make compounds.                                 •Share electrons that can be separated by chemical reactions. 

•Metal loses electrons= positive ions.  •Nonmetal gains electrons= negative ions

What happens when a metal & non metal react?

Opposute charges of ions strongly attract= metals & non metals react. 

•2 or more Atoms share an electron    •e.g. water, hydrogen chloride gas, carbon monoxide. 

Seperate soluble substances in a mixture. 

1) Draw line in graphite pencil.             2)Add spot of ink from capillary tube on line & place filter paper In beaker                                                     3) Place lid to stop evaporation.             4) Solvent goes up paper, carrying ink with it.                                                      5) Take paper out of beaker & leave to dry. 

•Not putting on a lid.                      •drawing line in pen.                               •placing base line into solvent. 

Seperates Insoluble solids from liquids. 

1) Grind mixture.                                     2) Put mixture into water & stir with glass rod, Salt will dissolve & sand won’t.                                                     3) Filter mixture - salt water passes through filter paper.                              4) Evaporate water from salt to form salt crystals. 

Filtration & Crystalisation METHOD.    (Seperating rock salt (sand & salt)= salt dissolves.)

2 Ways to seperate soluble solids from solutions: 

1) Pour solution into evaporating dish & heat, some solvent will evaporate.        2) After evaporation, remove dish from heat & leave to cool.                               3) Salt will form into crystals.                  4) Filter crystals from solution & leave in warm place to dry= Drying oven of desiccator. 

1) Pour solution into evaporation dish.   2) Heat solution, crystals will start to form.                                                        3) Keep heating until all there is left is dry crystals. 

1) Solution is heated in flask, part of solution that has the lowest boiling point evaporates first.                            2) Vapour in a condenser cools, condenses & is collected in a beaker. 

- Can only seperate things with different boiling points. 

1)Put mixture into flask & place fractionating column on top & heat.       2)Different liquids will evaporate at different temperatures due to boiling points.                                                    3)Liquid with lowest BP evaporates first & reaches top of column.                                                     4)Raise temperature so liquids with higher BP evaporate.        =or else Liquid with higher BP will only reach short way & condense into flask as top of column is coolest. 

Fractional distillation METHOD.              = Seperates mixture of liquids e.g. crude oil. 

•Atoms are solid spheres with different elements that cannot be divided. 

•Plum pudding model= ball of positive charge with electrons IN it. 

•Nuclear model=all mass is in nucleus. -Nucleus & a cloud of electrons.           -Discovered through the alpha particle experiments. ———-> Expected alpha particles to pass through sheet of gold- plum pudding model was wrong as alpha particles DEFLECTED 

•Nuclear model= suggested that electrons are contained in shells that orbit the nucleus. 

Elements arranged by ATOMIC WEIGHT. •James Jadwick provided evidence to show existence of neutrons. 

•left gaps in periodic table for undiscovered elements- predicted the element properties. 

How can you tell how many electrons an element has on its outer shell?

Alkali Metals.                                          •very reactive. •soft, low density.    •form ionic compounds with nonmetals •react vigorously with water=hydrogen •react with chlorine= salt.                     •react with oxygen= metal oxide 

•increase reactivity.                             •lower melting & boiling points           •higher relative atomic mass. 

Hologens.                                        •form ionic bonds with metals                 •can share electrons with non metals. •can displace weaker halogens

•less reactive.  •higher Melting & BP.   •higher relative atomic masses. 

•Flourine= orange.                                  •bromine= red.                                      •chlorine= green.                                   •iodine= purple. 

Noble gases= 8 electrons in outer shell •Unreactive due to full outer shell.      •colourless gases.                                •non flammable.                         

•increase Boiling & melting point= because electrons increase, making greater intermolecular forces.              •increasing relative atomic mass. 

-Lose electrons & form positive ions.      •strong •malleable •high melting & BP. •Conductors= delocalised electrons 

-Form negative ions.                               •dull •lower density •brittle                 •lower boiling & melting points.  

•Made when electrons are transferred to achieve a full outer shell.                   •Charged particles.                              

Which groups are most likely to form ions?

•metals lose electrons & form positive ions.                                                       •non metals gain electrons & form negative ions.  

Ionic bonding= When a metal & non metal react:

The number of electrons lost or gained is the same number as the charge.      •2 electrons lost = 2+.                         •3 electrons gained = 3-

When atoms share electrons to achieve a full outer shell.                                     •Positively charged nuclei are attracted to shared electrons=strong attraction by electrostatic forces.           •Happens in compounds of non metals & metals

=Molecules containing few atoms joined by covalent bonds.                      •Strong covalent bonds                          •weak forces of attraction.                     •low melting & boiling points                  •gases or liquids at room temp.           •can’t conduct electricity= aren’t charged, no free ions or delocalised electrons. 

•opposite ions closely packed together & held by electrostatic forces of attraction. 

•high Melting & Boiling points.               •Can’t conduct electricity when solid becaus eions are held in place.              •can conduct when molten as ions are free to move. 

• Lots of energy is needed to overcome electrostatic bonds. 

Why does an element have a high melting point?

=Long chain molecule that is formed by joining lots of smaller molecules together by covalent bonding. 

• solid at room temperature.                   •intermolecular forces are still weaker than ionic or covalent bonds= because they have lower boiling points than ions. & giant molecular compounds. 

=Atoms bonded by strong covalent bonds.                                                   e.g. Diamond, Silicon dioxide, graphite. 

•4 CARBON ATOMS, COVALENT BOND •Very hard.                                               • High melting & boiling point.               •Doesn’t conduct electricity= no free electrons or ions. 

•Each grain of sand is one giant covalent structure of silicon & oxygen. 

•3 CARBON ATOMS, COVALENT BOND •each carbon has 1 delocalised electron.                                    •Slippery= Hexagon shape sheets with no covalent bonds between layers so layers slide over eachother.                   •useful as a lubricant.                             •high melting point.                               •conducts electricity & thermal energy= delocalised electrons. 

•One layer of graphite hexagons            •very strong •light                  •conducts E——> useful in electronics

=molecules of carbon shaped like tubes or hollow balls.                             •NANOTUBES - hollow cylinders that conduct electricity & super strong-used in NANOTECHNOLOGY to strengthen materials without adding weight & electronics.                        •can cage other molecules-useful to deliver drugs into a body.                    •used for CATALYSTS- large SA.            •used for lubricants.                   

•conducts electricity= delocalised electrons in outer shell.                          •Strong electrostatic attraction between positive metal ions & shared negative electrons.                                  •High melting & Boiling points              •conductors of electricity & heat.        •malleable= layer of metal atoms slide due to a FIXED ARRANGED STRUCTURE

=Mixture of metals & other elements to make metal stronger/harder.                   •Hard——> Different atom sizes lead to a random arrangement making it difficult for layers to slide over eachother. 

•strong forces of attraction= fixed positions.                                             •don’t move- vibrate in fixed positions

•weak force of attraction= randomly arranged but close together.                •definite volume but no definite shape   

•very weak forces of attraction.        •expand when heated or pressure increases.                                                 •far apart & travel in straight lines.      •have most energy.                            •no definite shape or volume. 

What is it called when a solid becomes liquid?

What is it called when a liquid becomes gas?

What is it called when a gas becomes liquid?

What is it called when a liquid becomes solid?

What happens if temperature & energy increases?

What happens if energy & temperature decrease?

I’m a chemical reaction, no atoms are destroyed or created. 

Gas from atmosphere reacts with reactant to form product. 

What happens if there is an increase of mass?

•Gas escapes from reaction.                 •Reactant evaporates. 

What happens if there’s a decrease in mass?

1) warm acid with Bunsen burner, then turn off.                                                   2) Add insoluble base to acid bit by bit until no more reacts, excess will sink.    3) Filter out excess solid to get salt solution.                                                  4) Heat solution in water Bath to evaporate water. Stop heating & leave to cool. Crystals form.                            5) Filter again & dry crystals off. 

Making soluble salts with insoluble base PRACTICAL. 

How do you find the relative formula mass?

Ar x number of atoms of element.             ———————————————  x100. Mr of the compound. 

Percentage mass if an element in a compound =

What is it called when one reactant is used up?

Universal Indicator.                         OR PH probe & PH meter 

What is it called when an acid and base mix together?

Don’t fully ionise= become a reversible reaction. 

English (UK)

Flashcard

Diana Williamson

United Kingdom

DEFAULT (England)

Chemistry

Chemistry paper 1 AQA

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AQA Chemistry Paper 1 Condensed Notes PDF Free Download - Easy Revision for GCSE

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AQA Chemistry Paper 1 Condensed Notes PDF Free Download - Easy Revision for GCSE

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