Basic Facts For Mock Flashcards
How has the dalton model changed over time
It’s changed over time because of the discovery of sub atomic particles
Describe structure of atom
A nucleus containing protons and neutrons, surrounded by electrons in shells
Recall the relative charge and relative mass of a proton
Protons relative mass is 1 and charge is +1
Recall the relative charge and relative mass of a neutron
Relative mass is 1 and relative charge is 0
Recall the relative charge and relative mass of a electron
0.0005 relative mass
And a relative charge of -1
Why do atoms contain equal numbers of protons and electrons
To keep the overall charge neutral as protons and neutrons are oppositely charged.
What are isotopes
Atoms of the same element containing the same number of protons but different number of neutrons in their nuclei.
What is the mass number
TOP NUMBER- PROTONS AND NEUTRONS
What is atomic number
BOTTOM NUMBER-PROTONS
How to find number of electrons
Same as number of protons
BUT IF THERE IS A MINY + WITH A CHARGE U TAKE THE CHARGE AWAY FROM THE NUMBER OF PROTONS
E = p-c
What’s the electronic configuration number rule regarding shells
2-8-8
What number do we use when doing electronic configuration
ATOMIC NUMBER (BOTTOM)
Describe some characteristics of a giant ionic lattice
Very high melting and boiling point because of many strong electrostatic forces of attraction.
Solid at room temperature
Brittle
No free electrons so it doesn’t conduct electricity
Give example of atoms with a giant ionic lattice
Sodium chloride
Potassium chloride
What is an ionic bond
Electrostatic forces of attraction between oppositely charged ions
What happens in ionic bonding
Metal atoms give electrons to the non metal atoms.
The metal atoms become positive ions and non metal atoms become negative ions.
What happens in covalent bonding
Non metals combine together by sharing electrons
Give me an example of a weak covalent bond and describe what it is - properties
Water
It has weak intermolecular forces
Low melting and boiling point
Strong covalent bond
Give me an example of a giant covalent bond and describe the characteristics
Graphite and diamond Weak forces between layers Conducts electricity Sea of electrons High melting and boiling point
Describe characteristics of a metal
Malleable
High melting and boiling point because of strong electrostatic forces of attraction
Sea of electrons- conducts electricity
Organised layers of metal ions
Describe characteristics of a non metal
Lower melting and boiling point
Don’t conducts electricity
Good insulator
Weak electrostatic forces of attraction
What is sublimation
Give example
Solid that turns straight to a gas without passing through the liquid phase
Dry ice- solid carbon dioxide
How does a gas turn into a liquid
Condensing
Describe structure of periodic table
Elements are arranged in order of increasing atomic number in rows called periods
Elements with similar properties are places In the same vertical columns called groups
What is a neutralisation reaction
A reaction between an acid and a base
What is an acid alkali neutralisation
A reaction between hydrogen ions (h+) from the acid reacting with hydroxide ions (oh-) from the alkali to form water.
Difference between pure substance and mixtures
Pure substance only contains one kind of compound/element
Whereas a mixture is a combination of different types of substances and mixtures all together
How is chromatography carried out
A spot of the mixture is placed near the bottom of a piece of chromatography paper and the paper is then placed upright in a solvent. As solvent soaks up the paper it carried the mixtures with it. Different components of the mixtures will move up at different rates
How do identify pure substances from mixtures in chromatograms
A pure substance will only produce one spot on the chromatogram- one colour whereas a mixture will contain many different colours
What is distillation
Describe process
Process in which can be used to separate pure liquids from a mixture of liquids.
Heat source heats liquids
One liquid evaporates, cools and condenses in the Condensing tube.
Pure liquid then drops into beaker
E.g. Ethanol from water
What is fractional distillation and explain process
Separating mixtures into different parts in relation to their boiling points
A beaker containing liquid is heated, hot vapour them rises in the fractionating column. The one with the coolest boiling point rises first.
Vapour passes into the condenser and then gets released out other side
What is fractional distillation used for
Separating crude oils
Properties of the small molecules that have a low boiling point
Example
Flows easily
Evaporates quickly
Ignites easily
E.g. Petrol
Properties of large molecules that have high boiling points
Example
Evaporate slowly
Doesn’t flow easily
Doesn’t ignite easily
E.g. Fuel oil
Water purification steps
Water from source goes into a sedimentation tank where the large particles settle at the bottom and are removed
It then goes into a filtration tower which filtrate the small particles.
Chlorine is added to kill bacteria
Drinking water is stored
Still not pure- smallest particles can be removed by distillation and evaporation
How did Mendeleev predict existence of properties of some elements not yet discovered
Worked out the atomic masses of missing elements and so predicted their properties from those elements that shared Similar Atomic masses
Chemical test for hydrogen
Lit splint is put into test tube if pops and ignites hydrogen is present
Test for carbon dioxide
Bubble test gas through limewater and if lime water turns cloudy white then carbon dioxide is present
What is Crystallisation
A separation technique that is used to separate a solid that has dissolved in a liquid to make a solution
