Module 1: Properties and Structure of Matter Flashcards
What is a mixture?
A mixture is a combination of two or more pure substances
What is a heterogeneous mixture?
- Two or more substances that are mixed together but remain physically separate
- Has a composition which varies within the mixture
What are some examples of heterogeneous mixtures?
Dirt+water
Oil+water
What is a homogeneous mixture?
- Two or more substances that are mixed together but merge into a uniform phase
- Has a uniform composition within the mixture
What are some examples of homogeneous mixtures?
Salt+water
What are the six main physical properties used to seperate mixtures?
Magnetism
Solubility
Density
Boiling point
Melting point
Particle size
What are elements?
Elements are made of just one type of atom
What are compounds?
Compounds contain different types of atoms chemically bonded together in definite proportions
What is the solvent?
It is the substance which dissolves in the solute
What is the solute?
It is what the solvent is dissolved in
What is a suspension?
A suspension is a heterogeneous mixture, with visible distinguishable parts, that forms when a substance does not dissolve significantly
What are some examples of suspensions?
Chalk in water
Red blood cells in plasma
What is a colloid?
It is a mixture of particles that consists of smaller clusters of ions or molecules these molecules do not settle over time
What are some examples of colloids?
Milk
Mayonnaise
What is sublimation?
It is the change of state from solid to directly gas
What is deposition?
It is the change of state from gas to directly solid
What are the three main parts to the particle model?
- Matter is made up of particles that cannot be made smaller by either compression or further division
- The particles are in constant motion and are attracted to one another, weakly and strongly
- The particles are not necessarily atoms
What can’t the particle matter explain?
The model does not include a measure of forces between the particles therefore, the temperature at which a material changes state cannot be predicted
What property is used in filtration?
Particle size (solid in liquid)
What is the filtrate?
The liquid that has been filtered out during filtration
What is the residue?
It is the solid which is left on the filter paper after filtration
What is a volatile liquid?
A liquid that easily becomes a vapour is called volatile
What is the property used in distillation?
Boiling temperature
When is distillation used?
To seperate two liquids with at least 50 degrees difference in their boiling points
What is fractional distillation?
It is similar to distillation but their a small glass beads which mean that liquids with similar boiling points can be separated
What property is used in evaporation?
Boiling temperature
When is evaporation used?
When separating a solution with a solid dissolved in it
What are some characteristics of metal?
Lustrous
Malleable
Ductile
High melting/boiling points
Good conductors of electricity and heat
What is an alloy?
An alloy is a physical mixture of a metal with a small amount of some other element
What are some characteristics of non-metals?
Not malleable
Not ductile
Dull in colour
Lower in melting/boiling points
Poor conductors of electricity and heat
What are metalloids?
Metalloids are elements that have some metallic and non-metallic properties
What are chemical properties of elements?
Chemical properties relate to how easily an element undergoes chemical change
What are physical properties of elements?
Physical properties describe features that can be observed or measured
What are the periods on the periodic table?
The horizontal rows
What are the groups on the periodic table?
The vertical columns
What is electrostatic attraction?
Negative particles attract positive particles
How do you calculate the neutrons?
Mass number - atomic number
What is an isotope?
They are atoms that have the same number of protons but different number of neutrons
What are radioisotopes?
Isotopes which are radioactive
What type of radiation can be released during particle decay?
Alpha particles
Beta particles
Gamma radiation
What are alpha particles?
They are two protons and two neutrons which is a helium nucleus
When are alpha particles emitted?
When the nuclei has too few neutrons to be stable
What are the characteristics of alpha particles?
Low energy
Travels no further than a few centimetres
Can be stopped by a sheet of paper
What are beta particles?
A neutron is converted to a proton so the atomic number of the element increases by one
When are beta particles emitted?
When the nuclei has too many neutrons to be stable
What are the characteristics of beta particles?
High energy
More penetrating power that alpha particles
Can be stopped by aluminium plate several cm thick
What are the characteristics of gamma radiation?
High energy electromagnetic radiation
Great penetration power
Can only be stopped by thick lead
What is the standard to which all masses are compared to?
Carbon 12
Which is given the mass of exactly 12
What is the flame test?
It is a simple method that can be used to determine the identity of a metal sample
How does the flame test work?
When the metal atoms are heated, they give off light of a characteristic colour
How can an emission spectra be used?
Each emission spectrum is unique for a particular element and can be used to identify the elements present
What is ionisation energy?
It is the energy needed to remove an electron from an atom
What is the electron configuration?
It is the simple way of showing the electron configuration
ie. Oxygene: 2,6
What are valence electrons?
The electrons in the outer shell
What is the formula for how many electrons a shell can hold?
2n^2
n - shell number
What is the Bohr Model?
Electrons are viewed as tiny, hard particles that revolve around the nucleus in circular orbits
What are dispersion forces?
The forces of attraction between non-polar molecules. Is the weakest type of force.
What are dipole dipole forces?
Only occur in polar molecules and is relatively weak
What is hydrogen bonding?
Is a special form of dipole–dipole force which only occurs between molecules in which a hydrogen atom is covalently bonded to an oxygen, a nitrogen or a fluorine atom
When is coloured light produced in an emission spectra?
When electrons move from higher to lower energy levels
