Additional Chemistry Flashcards
The number of protons is equal to the number of what?
The number of electrons
What charge do PROTONS have?
Positive
What charge do NEUTRONS have?
Neutral
What charge do ELECTRONS have?
Negative
How many electrons can occupy each shell around an atom?
1st shell= 2
2nd shell= 8
3rd shell = 8
What is the nucleus of an atom made up from?
Protons and neutrons
What does the MASS NUMBER of an element tell you?
The total number of PROTONS and NEUTRONS in the atom.
What does the ATOMIC number of an element tell you?
The number of PROTONS in the atom.
What is the name of positively or negatively charged atoms?
Ions
Elements in groups 1 & 2 are metals or non metals?
Metals
FILL THE GAPS
Group 1&2 elements ______ electrons to form ______ ions or ______.
Lose
Positive
Cations
FILL THE GAPS
Group 6 & 7 elements ______ electrons to form _____ ions or _______.
Gain
Negative
Anions
The rows of the periodic table are called what?
Periods
The columns of the periodic table are called what?
Groups
The period number is the same as the number of what?
Electron shells
The group number is equal to what?
The number of electrons on the outer shell.
The process of atoms transferring electrons, is called what?
Ionic bonding
Ionic compounds have high melting and boiling points; true or false?
True (due to their very strong bonds between ions - takes a lot of energy to break bonds.)
Ionic compounds can conduct electricity in which two states?
Aqueous and molten
When sodium and chlorine combine, the compounds name is ….?
Sodium chloride
When three or more elements combine, including oxygen, the compounds name will be something _____?
ATE
Are group 6 & 7 elements metals?
NO! They are non metals
When sodium gives up an outer electron and gives it to the chlorine atom;which element becomes positive and which becomes negative?
Sodium = positive = Na+ Chlorine = negative = Cl-
Ionic compounds can be shown through what sort of diagram?
Dot and cross
Ionic compounds produce what structure?
Regular lattice structure
If one hydroxide ion (OH-) is needed to balance one sodium ion (Na+), what would the formula for this compound be?
NaOH (sodium hydroxide)
Two chloride ions (Cl-) are needed to balance one magnesium ion (Mg2+), what would the formula be for his compound?
MgCl2 (magnesium chloride)
What two things make up the structure of an atom?
The nucleus and the electrons
Name a technique to separate two immiscible liquids
Separating tunnel
How are miscible liquids separates?
Fractional distillation
What is the use of chromatography?
Identifying substances
How can you identify different substances in a mixture through chromatography?
Different substances wash through we filter paper at different rates.
A chromatogram with four spots means what ?
There are at least 4 different substances in the sample mixture.
Graphite creates sheets of carbon atoms meaning it does what ?
Slide over each other
Give two examples of what graphite is used for ?
A lubricant
Pencils
Graphite is a good conducted of electricity.
TRUE or FALSE
TRUE: there are lots of space electrons
What does the word ‘miscible’ mean ?
When liquids mix together
What is the Rf value in terms of spots on chromatogram?
The ratio between the distance travelled by the dissolved substance and the distance travelled by the solvent.
If one hydroxide ion (OH-) is needed to balance one sodium ion (Na+), what would the formula for this compound be?
NaOH (sodium hydroxide)
What does the term ‘soluble’ mean?
A substance which CAN be dissolved (especially in water)
What does the term ‘insoluble’ mean?
A substance which CANNOT be dissolved
What reaction can be used to make insoluble salts?
Precipitation reaction
Describe the process of preparing an insoluble salt…
- ) react two SOLUBLE salts together in a beaker.
- ) wait for the precipitate to form; filter the precipitate off.
- ) rinse the solid with distiller water - to ensure all soluble salt ions aren’t present.
What colour does potassium turn a flame?
Lilac
What colour does sodium turn a flame?
Yellow/orange
What colour does calcium turn a flame?
Brick red flame
What colour does copper turn a flame?
Blue - green flame
How do you test for carbonates being present in a solution?
Check for Co2 - LIMEWATER TEST
How do you test for sulphate ions?
Add dilute HCl and barium chloride solution; a white precipitate will form meaning the compound contains sulfate.
How do you test for chloride ions?
Add dilute nitric acid and silver nitrate solution. A chloride will show a white precipitate being formed.
When atoms SHARE electrons, it’s called what?
Covalent Bonding
Covalent bonds form what?
A molecule
Give two examples of giant molecular covalent substances.
Diamond and graphite (both only made by carbon atoms)
How many covalent bonds do carbon atoms form in a diamond?
Four!!
What is a diamond good for?
Cutting tools
Why doesn’t diamond conduct electricity?
No free electrons
Graphite carbon atoms form how many covalent bonds?
Three!!
Why do atoms share electrons?
To have a complete outer shell.
Simple molecular covalent substances have weak attraction between molecules meaning…
They have very low melting and boiling points
List four things about GIANT molecular covalent substances…
- high melting and boiling points
- don’t conduct electricity (except graphite)
- insoluble in water
- strong covalent bonds
- no charged ions
What is the Rf value in terms of spots on a chromatogram?
The ratio between the distance travelled by the dissolved substance and the distance travelled by the solvent.
How do you work out the Rf value?
Rf = distance travelled by substance
_____________________________
Distance travelled by solvent
Elements in group 1 & 2 are all what?
Metals
Name two typical properties of metals..
- bendy
- great conductors
Transition metals have two properties which metals don’t, what are they?
- high melting points
- form colourful compounds
Atoms in metals are held together by what?
Metallic bonds
What does a metals ‘giant structure’ consist of?
Positive ions and free electrons
Metallic bonds in metals allow the electrons to do what?
Move freely around
Because electrons in metals are able to move freely through their structure, it means metals are good at what?
Conducting electricity
Metals have high boiling points and are insoluble, why is this?
Because they have a giant metallic structure and strong bonds
What allows metals to be bent and shaped?
Their layers of atoms - sliding over each other
Metals in group one are called what?
Alkali metals
Name two properties of alkali metals which make them different to other metals?
They’re soft
Low melting points
Group one elements react with water to form what?
Hydroxides.