C1-Atomic structure and the periodic table Flashcards
How many atoms are there in the universe?
10⁷⁸ -10⁸²
What are vertical columns called in the periodic table?
Groups
What are horizontal rows called in the periodic table?
Periods
Where are metals on the periodic table?
On the left
Where are non-metals on the periodic table
On the right
What are metalloids?
Elements that have some metallic and non metallic properties
What is an element?
A substance made up of one atom only
What is a compound?
A substance formed by the chemical union of two or more elements
What is a mixture?
Different types of atoms or compounds that aren’t chemically bonded
What are all substances made up of?
Atoms
What do chemical reactions show?
The reactants (the substances you started with) and the products (the new substances made)
What is the law of the conservation of mass?
The total mass of the products formed in a reaction is equal to the total mass of the reactants
What are the state symbols for:
1) Solids?
2) Liquids?
3) Gases?
4) Aqueous solutions?
1) (s)
2) (l)
3) (g)
4) (aq)
Fill in the blanks:
A ……….. is dissolved by a …………. which creates a …………….. .
- Solute
- Solvent
- Solution
What are 6 methods of separating mixtures?
- Magnetism
- Crystallisation
- Simple distillation
- Fractional distillation
- Filtration
- Paper chromotography
How does magnetism work?
Magnetism is used to seperate magnetic elements from mixtures. By hovering a magnet over a mixture containing a magnetic element such as Iron, Cobalt or Nickel, the magnetic element will be pulled out
How does crystallisation work?
Crystallisation is used to produce solid crystals from a solution-a solution is warmed and some of the solvent evaporates leaving crystals behind
How does simple distillation work?
Simple distillation is used to seperate a solvent from a solution. Due to the dissolved solute having a much higher boiling point than the solvent, the solution is heated, solvent vapour cools in a condenser and the pure solvent is extracted.
How does fractional distillation work?
Fractional distillation is used to separate different liquids from a mixture of liquids such as extracting different fuels from crude oil. Due to the liquids having different boiling points, when the mixture is heated:
* The vapours rise through a column which is hot at the bottom and cooler at the top
* The vapours condense when they reach a part of the column that is below the temperatures of their boiling point
What are the two different ways liquid can be obtained in fractional distillation?
- By collecting different liquids from different parts of the column
- By continuing to heat the mixture to increase the temperatures in the column
How does filtration work?
Filtration is used to seperate an insoluble solid from a liquid-such as sand an water or excess reactant from a reaction mixture. When a mixture is poured into filter paper, small molecules and dissolved ions can fit through but not larger particles
How does paper chromotography work?
Paper chromotography is used to seperate mixtures of soluble substances such as inkes or dyes. As paper dotted with the ink absorb the solvent they spread up the paper.
What is the stationary phase in paper chromotography?
The paper
What is the mobile phase in paper chromotography?
The solvent
What does paper chromotography produce?
A chromatogram
What did Ancient Greeks think that the entire universe was made up of?
The 5 Elements-Earth, Fire, Water, Air, Aether
What did both greek philosopher Democritus and John Dalton in 1803 theorise about atoms?
That atoms were like tiny, hard spheres that could be rearranged
What did J.J. Thomson discover about atoms?
Electrons by using cathode rays-he was the scientist to show that atoms are made up of different things and he created the ‘plum pudding model’ which was negative electrons embedded in a sphere of positive charge.
What did Ernest Rutherford discover about atoms?
He designed an experiment where he fired positively charged alpha particles at a thin piece of gold. Most of the particles went straight through the foil but a few were scattered in different directions. This led to the nuclear model of the atom where:
* The mass of the atom is concentrated in the centre (nucleus)
* The nucleus is positively charged
* The atom is mostly empty space
What did Niels Bohr discover about atoms?
That electrons orbit the nucleus in shells at specific distances and energy levels. Further experiments led onto the idea of the nucleus.
What did James Chadwick discover about atoms?
He found evidence of sub-atomic particles called neutrons which led to another development of the atomic model that we still use today.
What is the relative atomic mass?
The mass of an atom compared to 1/12th of a carbon-12 atom
What is the charge and relative atomic mass of a:
1)Proton?
2)Electron?
3)Neutron?
1) +1, 1
2) -1, 1/2000
3) 0, 1
What is the radius of an atom?
1 x 10⁻¹⁰m
What is the radius of a nucleus?
1 x 10⁻¹⁴m
What is the atomic number?
The number of protons-it defines what element something is
What is the mass number?
The number of protons+neutrons-it makes up the vast majority of the mass of the atom
What is an ion?
An atom with a charge
If an Oxygen atom gains 2 electrons how would you write the formula symbol?
O²⁻
If a Lithium atom loses 1 electron how would you write the formula symbol?
Li⁺
What is are isotopes of an atom?
Atom that have the same number of protons with different numbers of neutrons
Give some isotope examples
- hydrogen-1, hydrogen-2, hydrogen-3
- carbon-12, carbon-13, carbon-14
What is the formula for relative atomic mass?
% abundance of all isotopes x by their mass/100
What similar and different properties to different isotopes have?
They have identical chemical properties but differing physical properties
What are the electrons in an atom arranged in?
Energy levels-shells
What is the order of electrons in shells?
1st shell-2
2nd shell-8
3rd shell-8
4th shell-2
(2,8,8,2)
What is the lowest energy shell?
The 1st shell
What does the amount of electrons in the outer shell signify and determine?
The group number and it determines how the element will react
What does the number of shells signify?
The Period number
What were John Dalton’s ideas about the periodic table?
He produced a table showing his ‘law of octaves’ and he ordered elements in order of atomic weights however he didn’t take into account new element discoveries and other scientists ridiculed him and refused to accept his theory.
How did Dmitri Mendeleev produce a periodic table?
Mendeleev placed elements in order of atomic mass and left gaps for elements that hadn’t yet been discovered as he took into account properties of the elements and their compounds. Due to different isotope’s masses he didn’t arrange elements in order of mass and rather my their properties-this problem was a mystery for decades until the neutron was discovered by James Chadwick. His periodic table is similar to our current one
How many electrons do noble gases have in the outside shell?
0
What are the properties of noble gases?
Unreactive, Boiling point and Density increases down the group, noble gases shine brightly when electricity is passed through them
How many electrons do halogens have in their outer shell?
7
What are the properties of halogens?
reactive, less reactive down the group, higher boiling point and density down the group
How many electrons do Alkali metals have in their outer shell?
1
What are the properties of Alkali metals?
Reactive, boiling point decreases down the group, reactivity increases down the group, they react with water
What are displacement reactions with halogens?
A more reactive halogen will displace a less reactive halogen from solutions of it’s salts
What increases as the number of shells increase of an atom
Shielding
