Module 1: Properties and Structure of Matter Flashcards
How many Kelvins is 0 degrees celcius?
273.15K
What is an element?
An element consists of one type of atom that cannot be broken down into anything simpler.
What is an example of an element?
oxygen, hydrogen etc. (anything on the periodic table
What is a compound?
A compound consists of two or more types of atoms that are chemically bonded together in a fixed ratio. They can be broken down chemically into simpler compounds or individual elements.
What is an example of a compound?
H2O, CO2 etc.
What are the two types of impure substances (mixtures)?
- Homogeneous mixture
- Heterogeneous mixture
What is a homogenous mixture and give an example.
Homogenous mixtures are evenly mixed, the properties and composition remain the same throughout the mixture. Eg. steel, detergent, sugar etc.
What is a heterogenous mixture and give an example.
Heterogenous mixtures are NOT evenly mixed throughout. Eg. a mixture of oil and water or milo and milk.
What is the equation to calculate the percentage composition of a substance?
% weight = mass of component in sample (g) / total mass of sample (g) x 100
Name 6 seperation methods.
Sieving, Sedimentation/decantation, filtration, evaporation, distillation, separating funnel.
What is sieving?
Sieving is used to seperate solids of different particle sizes. The sieve retains the larger particles.
What is sedimentation/decantation?
It is a separating method that is based on the density of particles. The larger/ more dense particles seperate and ‘settle’ due to gravity at the bottom of the mixture.
What is filtration?
Filtration separates mixtures based on particle size, as a mixture is poured through filter paper leave insoluble residue behind, with filtrate (usually liquid) passing through.
How is evaporation used to seperate mixtures.
Evaporation is used to seperate liquids with differing boiling points. The liquid is held to heat causing the substance with the lowest boiling point to evaporate, leaving the dissolved solution behind.
How is distillation used to physically seperate a mixture.
Distillation heats the mixture, causing the substance with the lowest boiling point to turn into vapours and seperate. (fractional distillation is often used, which uses multiple different substances with differing boiling points).
What is a cation? Give an example.
A cation is a metal ion and is positively charged. eg. lithium, ammonium, iron etc.
What is an anion? Give an example.
An anion is a non-metal ion and is negatively charged. eg. chloride, phosphate, hydroxide etc.
How do you name a metal & non-metal? Give an example.
- Name the metal first.
- Name the non-metal followed by the suffix ‘ide’. eg. magnesium oxide.
How do you name two non-metals?
- Name the first non-metal and add the required prefix (eg. mono, di, tri, tetra etc.).
- Name the second nonmetal with the required prefix and add the suffix ‘ide’.
What are the ten prefixes used with naming molecules?
Mono=1
Di=2
Tri=3
Tetra=4
Penta=5
Hexa=6
Hepta=7
Octa=8
Nona=9
Deca=10
What is a group of the periodic table and provide an example.
It is the vertical rows. They tend to have similar properties. Eg. alkaline metals, noble gases, hallogens etc.
What is a period of the periodic table?
The horizontal rows
Name five physical properties of elements.
lustre, odour, solubility, melting & boiling points, density, conductivity, malleability, ductility, colour etc.
Name five chemical properties of elements.
Flammability, combustibility, toxicity, oxidation, reactivity.
What is a physical property?
It is a property that can be observed without changing the identity of the substance.
What is a chemical property?
It is a property that can only observed by changing the idenity of the substance.
What are some properties of alkali metals?
most reactive going down the group, low melting & boiling point, low density, soft.
What are some properties of noble gases?
most stable/unreactive/inert (full outer electron shell), colourless, odourless.
What is an isotope?
An atom of the same element that has a different neutron number.
What is a molecule?
Two or more atoms bonded together.
What is a compound?
A molecule that contains multiple different elements.
What is the schrödinger model?
It suggests that electrons have both wave-like and particle-like properties and that electrons move around the nucleus in orbitals (volume of space that has a high probability of finding an electron).
What is the bohr model?
The bohr model described electrons as particles as they move around the nucleus in fixed orbitals.
How many electrons are found in each orbital?
2 in the first orbital, 8 electrons in the rest.
What is an unstable isotope?
Unstable isotopes are radioisotopes that emit energy from the nucleus in the form of radioactive decay as they attempt to become stable.
What are the three types of radiation emitted from a radioisotope?
Alpha, beta, gamma
What is the atomic radius?
It is the distance from the atoms nucleus to the atoms outer-most electron cloud.
What is the ionic radius?
It is the distance between the nucleus and outer most electrons of an ion (cation nor anion).
What is ionization energy?
It is the energy required to remove an electron.
What is electronegativity?
The ability of an atom to pull electrons towards itself in a bond. (wants electrons).
What is a intramolecular force?
The interactions within molecules.
What is a intermolecular force?
The interactions between molecules.
What is allotropy and provide an example.
It is the ability of an element to adopt multiple different physical forms due to differences in bonding. Eg. carbon as graphite and as diamond.
What is an ionic bond?
The transfer of electrons between a metal and non-metal. Where the metal wants to get rid of electrons and the non-metal wants to gain electrons. This requires a larger difference in electronegativity between atoms.
What bond is defined as electrostatic attractions between a cation and an anion?
An ionic bond.
What is a covalent bond?
When two non-metal atoms share valency electrons due to the attractive forces between the nucleus & electrons of atoms being stronger than repulsive forces.
What is the difference between a poplar and non-polar covalent bond?
A polar covalent bond is the sharing of electrons unequally between atoms whilst a non-polar covalent bond is sharing of electrons equally.
What is a covalent molecular?
Molecules that have covalent bonds.
What is a covalent netwrok?
Are compounds whose atoms are bonded by covalent bonds in a continuous network.
What is metallic bonding?
This bond occurs between two metals where valence electrons are not held together tightly rather they are delocalised. It is held together by the attraction between the cations (+) and delocalised electrons (-).
