Topic 1 Flashcards
states of matter, elements compounds and mixtures, atomic structure
What are the three states of matter
Solid, liquid and gas
What are the physical properties of solids
- high density
- cannot be compressed
- fixed shape
- cannot diffuse
- doesn’t exert any pressure
What are the physical properties of a liquid
- fairly high density
- cannot be compressed
- takes up shape of the bottom of the container
- can diffuse
- can exert some pressure
Physical properties of gases
- low density
- can be compressed
- no fixed volume or shape
- can diffuse
- exert a lot of pressure
How do you get from a solid to a liquid and what is the name of the process
Melting - heat up the solid
How do you get from a liquid to a solid and what is the name of the process
freezing - cooling down the liquid
How do you get from a liquid to a gas and what is the name of the process
evaporation/boiling - heat up the liquid
How do you get from a gas to a liquid and what is the name of the process
Condensing - cool down the gas
How do you get from a solid to a gas and what is the name of the process
Sublimation - heat up the solid
How do you get from a gas to a solid and what is the name of the process
sublimation - cooling down the gas
Explain the reasoning behind the bromine diffusion experiment
the bromine diffuses up against gravity and filled the containers evenly. The bromine particles moved via collisions with each other
What is a solvent
The liquid that does the dissolving
What is a solute
The solid that dissolves
What is a solution
A mixture that is made when a solute dissolves into a solvent
What is a saturated solution
A saturated solution can dissolve no more solute in that amount of solvent AT THAT TEMPERATURE
What does the term solubility in the units g per 100 g of solvent mean
The solubility of a solute in H2O at a given temperature is the maximum amount of it that it will dissolve in 100g of H2O at that temperature
element definition
A substance that contains one type of atom only. it cannot be broken down into anything simpler
compound definition
A substance that contains 2 or more different atoms CHEMICALLY BONDED
Mixture definition
a substance that contains 2 or more different atoms NOT chemically bonded
Atom definition
The smallest part of an element that can exist on its own and has the characteristics of that element
What does filtration separate
Separating an insoluble solid from a liquid
What does evaporation/cyrstallisation separate
separating a soluble solute from a solution
What does simple distillation separate
Separates a solvent from its solution
What does fractional distillation separate
separates different liquids from a mixture of liquids
What does a separating funnel separate
Separates 2 immiscible liquids (e.g. water and oil)
What does chromatography separate
Separates mixture of soluble solids/ separates a mixture of dyes
What is the method for the chromatography experiment
- Draw a pencil line on chromatography paper
- Small spot of sample on pencil line; allow to dry
- Place chromatography paper in a beaker containing solvent to a height lower then the pencil line
- Place a lid on beaker
- Allow solvent to run up the paper until near the top
- measure the distance travelled by the solvent and the spots
- find Rf values
How do you calculate the Rf value
Distance travelled by substance (the dye) / distance travelled by solvent
Explain why dyes travel different distances up the chromatography paper
If the dye has a strong affinity for the mobile phase (the solvent) the dye will move far up the paper, but if the dye has a strong affinity for the stationary phase the dye will move slower. If the dye doesn’t move it means it is insoluble in that solvent
What are the relative masses of protons, neutrons and electrons
Protons - 1
Neutrons - 1
Electron - 1/1840
What are the relative charges of protons electrons and neutrons
Proton = +1
Electron = -1
Neutron = 0
What is the atomic number
number of protons in the nucleus
What is the atomic mass
number of protons and neutrons in the nucleus
Isotope definition
Atoms of the same element with the same number of protons and electrons but different number of neutrons
Why are isotopes chemically identical
They have the same number of electrons
How is the periodic table ordered
atomic number
How and why does does reactivity change going down the periodic table in Group 1
Reactivity increases.
- when group 1 want to lose an electron
- as you go down group 1 the outer electron is further away and more shieled from the positive nucleus
- this makes it easier to lose the outer electron making it more reactive
What are the similarities between group 1 metals when they reaction with water
They all:
- Fizz/ effervesce
- float
- move on the surface
- get smaller/ disappear
What happens when the alkali metals Li, Na and K react with oxyegn
Li - burns with crimson/ red flame to form a white solid
Na - burns with a yellow flame to form a white solid
K - burns with a lilac flame to form a white solid
What are the trends going down group 1
- Bigger atoms
- more reactive
- more dense
- lower m.p and b.p
- Softer to cut
Covalent bonding definition
The strong electrostatic attraction between the nuclei and shared electron pairs
Ionic bonding definition
The strong electrostatic attraction between oppositely charged ions
What is formed when a group 1 metal reacts with water
metalhydroxide + hydrogen
