C1 Better Flashcards
What are the rules for writing the symbols of elements?
First letter is a capital any others are lower case.
What is the list of all the elements called?
The periodic table
What is a compound?
2 or more elements chemically bonded together and so will have different properties to the elements on their own.
What is a mixture?
2 or more elements or compounds that are not chemically bonded so each part keeps its original properties.
What is an element?
A group of atoms that are the same.
Is gold an element, mixture or compound? Why?
Gold is an element as it is made only of gold atoms.
Is carbon dioxide an element, mixture or compound? Wy?
Carbon dioxide is a compound as it is formed from carbon and oxygen chemically bonded together.
Is salt water an element, mixture or compound? Why?
Salt water is a mixture as the water compound and salt compound are not bonded together.
How many atoms are in H2SO4?
H=2 S=1 O=4 Total= 7
How many atoms are in 3HNO3?
3H + 3N + 9O –> 15
What property does filtration exploit?
Solubility
What property does crystallisation exploit?
Boiling point
What property does simple distillation exploit?
Boiling point
What property does fractional distillation exploit?
Boiling point
What separation technique separates solids from liquids?
Filtration
What are the key steps of distillation?
Heating, evaporation, cooling, condensing
Advantages of simple distillation over fractional distillation?
Simpler setup, faster, consumes less energy
Disadvantages of simple distillation over fractional distillation?
Requires the liquids to have a large difference in boiling point and gives poorer separation.
Why do inks separate in chromatography?
Because of their mass and solubility.
What is the soluble part of a filtered mixture called?
Filtrate
What is the insoluble part of a filtered mixture called?
Residue
Why would you use filtration to separate a mixture of sand and water?
Because the water will filter through but the sand is not soluble so will form the residue.
Why would filtration not be a good method to separate salt and water?
Because salt is soluble in water so both the salt and the water would be in the filtrate.
What method would be suitable to separate a mixture of inks?
Chromatography as the ink particles will have different masses so travel different distance up the filter paper.
What was the plum pudding model of the atom?
Atoms were spheres with negatively charges electrons embedded in them
Which model of the atom was developed first?
The plum pudding model was developed before the nuclear model of the atom.
What is the nuclear model of the atom?
Atoms have a central nucleus and are surrounded by negative electrons.
What caused the development of the nuclear model?
The alpha particle scattering experiment which showed that most of the mass of an atom was in a central nucleus.
Who discovered the electrons?
Thompson in 1897
Who discovered the nucleus?
Rutherford in 1911 using the alpha scattering experiment.
Who discovered the nucleus?
Rutherford in 1911 using the alpha scattering experiment.
Who discovered the number of electrons on each shell?
Chadwick in 1932
What is in the nucleus of an atom?
Protons and neutrons
What part of an atom is not in the nucleus?
Electrons
What do the electrons sit on?
Shells
How many electrons can fit on each shell?
2, 8, 8
What is the charge of protons?
1
What is the charge of neutrons?
0
What is the charge of electrons?
-1
What is the mass of protons?
1
What is the mass of electrons?
Nearly 0
What is the mass of neutrons?
1
What size are atoms?
0.1nm in radius
What size is the radius of the nucleus compared to the atom?
1/10,000 of the atom
What does the atomic number tell us about an atom?
Number of protons/electrons
What does the atomic mass tell us about an atom?
Number of protons and neutrons
How do you calculate the number of neutrons?
Atomic mass- proton number
How does the period link to the electron configuration?
The number of shells
How does the group link to the electron configuration?
The number of electrons on the outer shell (valence)
What is an isotope?
Atoms of the same element with a different number of neutrons.
How do you calculate the atomic mass of an element?
(Mass x abundance) + (Mass x abundance) / 100
What is the electron configuration of sodium?
2,8,1
How are elements arranged in the periodic table?
By increasing number of protons.
Why is it called the periodic table?
Because similar properties occur at regular intervals (or periods).
What are the columns in the periodic table called?
Groups
What are the rows in the periodic table called?
Periods
How does the group number link to electron configuration?
Number of electrons on the outer shell (valence electrons)
How does the period number link to electron configuration?
Number of electron shells
What is the middle block of the periodic table called?
Transition metals
What is group 1 called?
Alkali metals
What is group 2 called?
Alkali earth metals
What is group 7 called?
Halogens
What is group 8 called?
Noble gases
Who developed the periodic table?
Dmitri Mendeleev
How was Mendeleev’s periodic table different from even earlier versions?
Mendeleev left gaps for undiscovered elements and switched elements around so each group had similar properties.
How was Mendeleev’s periodic table different from even earlier versions?
Elements were ordered by atomic mass not atomic number.
How was Mendeleev’s periodic table different from the modern one?
In the modern periodic table elements are ordered by atomic number and there are not gaps as more elements have been discovered.
Why are noble gases unreactive?
Because they have a full outer shell of electrons
What happens to the boiling point as you go down the noble gases group?
It increases.
Why do alkali metals all have similar properties?
Because they all have 1 electrons on their outer shell.
What is the product when alkali metals react with oxygen?
Metal oxides
What is the product when alkali metals react with chlorine?
Metal chloride
What are the products when alkali metals react with water?
Metal hydroxide + Hydrogen
Explain the trend in reactivity down group 1?
They get more reactive down the group.
Why do elements in group 7 have similar properties?
Because they all have 7 electrons on their outer shell.
Does mass increase or decrease going down group 7?
Increase.
Does melting point increase or decrease going down group 7?
Increase.
Does boiling point increase or decrease going down group 7?
Increase.
Does reactivity increase or decrease going down group 7?
Decrease.
Why can this reaction not occur? Iodine + Potassium Fluoride
Because fluorine is more reactive than iodine.
Compare the properties of alkali metals to transition metals.
Group 1 elements have lower melting points, are less dense, are not as strong but are more reactive.
What are the 3 key characteristics of transition metals?
When they form ions they can have more than one charge (e.g. Fe2+ and Fe3+), they form coloured compounds and are used as catalysts. (The 3 Cs- charge, colour and catalyst).
