The Chemical Earth Flashcards
1.2
Identify the difference between elements, compounds and mixtures in terms of particle theory
Elements: all atoms are the same, properties are always the same
Compounds: contains identical clusters of two or more different atoms
Mixtures: ingredients retain properties and can be separated
1.3
Identify mixtures, elements and compounds in earth’s spheres
Biosphere: Nucleic acids, fats
Lithosphere: free elements (gold, platinum), minerals
Atmosphere: mixture of gases
Hydrosphere: water, dissolved sea salts
1.4
Identify and describe procedure and property that separates solids of different sizes
Sieving
Difference in particle size
1.4
Identify and describe procedure and property that separates dissolved solids in liquids
Evaporation
Different boiling points
1.4
Identify and describe procedure and property that separates solids and liquids
Filtration
Difference in particle size
1.4
Identify and describe procedure and property that separates liquids
Decantation
Density
1.4
Identify and describe procedure and property that separates gases
Distillation
Boiling points
1.5
What is gravimetric analysis and why is it needed?
It is used to determine quantities by mass of substances present in a sample.
The parts are labelled as percentage compositions
2.1
What is the relationship between reactivity of an element and the likeliness of it being found naturally uncombined?
The more reactive an element is, the less likely it is to be found naturally uncombined.
2.2
What are the main properties of metals?
Lustrous, high conductivity and density
2.2
What are the main properties of semi-metals?
Low sheen, moderately dense and malleable, high thermal conductivity, low electrical conductivity (semi-conductor), high boiling point
2.2
What are the properties of non-metals?
Dull, low thermal conductivity, no electrical conductivity, low density and boiling point
2.3
Account for uses of metals in terms of physical properties
Metal e.g. Aluminium
Use for foil, cans, saucepans, roofing, because of lustre, malleability, corrosion-resistance
2.3
Account for uses of non-metals in terms of physical properties
They have a large range of properties, so have various uses
2.3
Account for uses of semi-metals in terms of physical properties
Also vary greatly - conductivity increased by liquids such as As or B
3.1
Describe the interaction of particles in solids
Particles are in a fixed position and are close together, but still slightly vibrate
3.1
Describe the interaction of particles in liquids
Particles roll over each other, change formation, but stay attached
3.1
Describe the interaction of particles in gases
Particles have large spaces between them, move a lot and diffuse easily.
3.2
Describe qualitatively the energy levels of electrons in atoms
Atoms have the same number of protons and electrons.
Energy levels in an atom increase as the amount of electrons in the shells increase.
3.3
Describe atoms in terms of mass number and atomic number
Mass number: depends on the number of protons and neutrons = protons + neutrons
Atomic number: the humber of protons in the nucleus of an atom, and the number of electrons in the shells
Mass number labelled at the top, atomic number at the bottom.
3.4
Describe the formation of ions
Ions form from atoms gaining or losing electrons.
Atoms with almost full shells gain an electron and become negatively charged.
Atoms will almost empty outer shells lose electrons and become positively charged.
3.5
Apply the Periodic Table to predict ions formed by elements
Coming from the left, the groups increase in positive charge (until 3)
Coming from the right, excluding Noble Gases, atoms increase in negative charge (until 3)
3.6
What are lewis electron dot structures
Diagrams that show the sharing of outer-shell electrons.
3.7
Describe the formation of ionic compounds in terms of attraction of opposite charge
Ionic bonds form when a cation and anion are attracted to each other.
They form with one metallic and one non-metallic element
