What are the earth's spheres?
what is the lithosphere made up of?
-silicon combined with oxygen
-contains hydrocarbons as oil
carbon hidden in calcium carbonate of chalk and limestone
What is the difference in strength between intermolecular forces and atomic bonds?
oxygen and hydrogen molecules have weak attractive forces between molecules of the same type.
-atomic bonds are really strong and require large forces and temperature to break bonds.
What are the properties of water?
less dense than gases like oxygen
-greater tendenacy to stick together because of look at photo
a water molecule is slightly positive on one side and slightly negative on the other side, which allows them to be more compact than other gases
-more dense than ice as can be compacted
-salts dissolve in water
Why is seawater salty?
-salt can dissolve in water
-rocks eroded in water
What is a covalent bond and which types of elements do they connect?
-non-metal and metal elements
-e.g. Na and Cl
-covalent bond is where the atoms share a pair or pairs of electrons
-atoms were held together because the positively charged nuclei of both atoms are attracted to the negatively charged shared pair of electrons
What id the strength of atomic and molecular forces in covantly bonded atoms?
-weak forces between molecules oxygen
-strong covalent atomic bonds
-results in low melting and boiling points, but it is very difficult to break the atomic covalent bonds
What is an ionic bond?
-the attraction between a positvely charged atomand anegatively charged atom
high melting and boiling points
So4(-2)-ionic but called a molecular ion
How can we test if positive ions are present in a compound and what are they?
-add adilute acid e.g. sodium hydroxide to compounds
-Positive if a precipitateof an insolublecompound forms during the reaction
-colour of the precipitate may help identify it
calcium Ca(2+)-white precipitate
copper Cu(2+)-Light blue precipitate
iron(11) Fe(2+)-Green precipitate
iron(111) Fe(3+)-Red-brown precipitate
Zinc Zn(2+)-white precipitate(excessis soluble)
How do you test if negative ions are present in a compound?
-By addind negative Group 7 elements to a dilute silver nitrate or barium chloride
acidify with dilute nitric acid, then addsilver nitrate
What are some examples of metal, mineralsand ores and where are they found?
-found in the lithosphere
-minerals are solids with atoms or ions arranged in a regualar lattice
e.g.carbon in the form of graphite and diamond
-silcon+oxygen join together as the mineral quartz
-many metals are oxides
-extracted by combining with carbon
-reduction reaction e.g. less oxygen
What are the differences and smilarities between diamond and graphite?
Diamond-giant covalent structure
-made up of carbon that is covalently bonded
-high melting and boiling point
-no free electrons
-does not conduct electricity therefore
Graphite- giant covalent structure
-made up of covalently bonded carbon atoms
- in graphite, each carbon is bonded to 3 or less crbon atoms in sheets
sheets are strong
weak intermolecular forces between the sheets
-free electrons allow the material to conduct electricity
What are some of the issues of extracting metal?
-how can the ore be reduced?
-the more reactive a metal is, the harder it is to reduce the ore
Is there a good supply of ore?-
-it may not be worth extracting
what are the energy costs?
-it may take a lot of energy to extract the metal
What is the impact on the environment?
-could release a harmful toxin
What is a metallic bond?
-positive protons swiming in a sea of negative electrons in a lattice
-electrons can move freely
-can conduct electricity
-high melting points
What are some properties and uses of metals?
-lead,mecury are poisinous
-waste can destroy habitats and soils
-lead used to make betteries for vehicles
-copper used for wire
-modern batteries use lithium, not toxic difficult to extract
How do you calculate the relative atomic mass of atoms?
How do you calculator the percentage of metal in a mineral?
=total mass of metal of atoms divided by gram formula mass
gram formula mass=relative formula mass in grams
How electrolysis is used to extract aluminium from its ore?
-used to extract only more reactive metals as others can be reduced using carbon
-negative electrode attracts positive Al(3+)
-Positive electrode attracts negative O(2-)
How is a metal made and recycled?