C1 Flashcards
What is an element ?
substances that are made up of only one type of atom
What is a period ?
Elements in the periodic table in rows
What are groups ?
The elements in the table are arranged in columns called groups .
How many groups are there ?
8
What is a compound ?
Different types of atom bonded together are called compounds
What is the nucleas made up of ?
Protons and neutrons
What orbits the nucleas ?
electrons
What do chemical equations show ?
The reactants and products
What is the law of conservation of mass ?
The total mass of the products formed in a reaction is equal to the total mass of the reactants .
What does insoluble mean ?
Doesn’t dissolve in a liquid
What does soluble mean ?
dissolves in a liquid
What is filtration used for ?
Filtration is used to seperate an insoluble solid from a mixture of the solid and a liquid / solution .
What is an example of filtration ?
Sand from a mixture of sand and water
What is the method of filtration ?
- place filter paper in a filter funnel above a beaker .
- The mixture of insoluble solid and liquid poured into the filter funnel .
- The filter paper will only allow liquid particles and soluble solids to pass .
- Insoluble solids do not pass through the filter paper and are left behind as residue .
What is filtrate ?
The liquid that passes through the beaker.
What is a dissolved solid ?
Something that has dissolved into a liquid , most likely water . For example sand .
What is crystilisation used for ?
This method is used to seperate a dissolved solid from a solution . A simple application of this is to heat a solution to its boiling point , remove the heat and leave the solvent to evaporate .
How do you obtain a sample of pure salt from the salt solution ?
You can do this by evaporating the water from the sodium chloride solution . When small crystals start to form around the edge of the solution , the rest of the water evaporates .
What happens in distillation ?
In simple distillation , a solution is heated and boiled to evaporate the solvent . The vapour that is given off then enters a condenser . This is an outer glass tube with water flowing through it that acts as a cooling ‘ jacket’ . Here the vapour is cooled and condensed back into a liquid for collection in a recieving vessel .
What is paper chromatography ?
A technique used to seperate and identify substances from mixtures .
What is the method for paper chromatography ?
A capillary tube is used to dab a spot of the solution on a pencil line near the bottom of the sheet . The paper is then placed standing in a solvent at the bottom of a beaker or tank . The solvent is allowed to soak up the paper , running through the spot which makes its way upward .
Who discovered that substances were made up of atoms ? What else did he discover ?
John Dalton in 1880 . He also suggested that each chemical element had its own atoms that differed from others in their mass .
Who discovered the electron and what was the model called that he suggested ?
J.J Thompson discovered the electron . He said that electrons were embedded in a cloud of positive charge . He called it the Plum pudding model .
Who was doing an experiment with alpha particles and gold paper ?
Geiger and Marsden students , Rutherford also .
What were the Geiger and Marsden students doing ?
Firing dense , positivley charged alpha particles at the thinnest piece of gold paper .
What did Rutherford suggest after the experiment with alpha particles ?
Rutherford suggested that the positive charge must be concentrated at a tiny spot in the middle of the atom . Otherwise the large , positive particles fired at the foil could never have been repelled back to the source .
Are Alpha particles positive or negative ?
positive
Are Gold particles positive or negative ?
positive
Who revised the model after Rutherford ?
Niels Bohr
What did Niels Bohr suggest about the atom ?
He suggested that the electrons must be orbiting the nucleas at set distances in certain energy shells .
What was the order of events for the history of the atom ?
- John dalton
- J.J thompson
- Geiger and Marsden students
- Rutherford
- Niels Bohr
- James Chadwick
Who discovered the existence of neutrons ?
james chadwick
What is the relative charge of a proton ?
+1
What is the relative charge of a neutron ?
0
What is the relative charge of an electron ?
-1
What are the masses of a proton and a neutron ?
1
What is the mass of an electron ?
too small
Where is the mass number on an element in the periodic table ?
at the top of the element
Where is the atomic number located on an element in the periodic table ?
At the bottom of the element
How do you work out the number of neutrons in an element using the periodic table ?
Mass number - atomic number = neutrons
How do you work out the number of protons and electrons using the periodic table ?
the atomic number
What happens to the electrons of a metal when it reacts with a non metal ?
The metal will lose an electron or electrons to become a positive ion .
What happens to the electrons of a non metal when it reacts with a metal ?
The non metal will gain an overall negative charge to become a negative ion .
What is an ion ?
An ion is charged group of atoms or atom .
What is an isotope ?
Atoms of the same element with different number of neutrons .
What will an isotopes physical propeties be like ?
They will have a different density
They may or may not be radioactive
How are electrons arranged ?
in a 2 , 8 , 8 structure
