AQA Combined Chemistry 5.1 Flashcards
Revision for Paper 1
What do all chemical symbols, e.g. Na and O, have to start with?
A capital letter
What is the name of the smallest part of an element that makes up all substances?
An atom
What is a mixture?
Two or more elements, or compounds, that are not chemically bonded together
Approximately how many different elements are there?
There are around 100 different elements
What is a compound?
1) Two or more elements
2) Chemically combined
What is the defintion of an isotope?
Atoms of the same element with a different number of neutrons
What are the names of the sub-atomic particles in the nucleus of the atom?
Protons and neutrons
What are the columns in hte Periodic Table called?
Groups
What are the rows in the Periodic Table called?
Periods
How are the elements in the Periodic Table arranged?
Atomic (proton) number
What similarities are there between elements in the same group?
1) Same number of electrons in outer shell/energy level
2) Similar properties
What does the Group Number tell you about the electrons in an element?
Number of electrons in outer shell/energy level
Who designed a Peridioc Table that left gaps for undiscovered elements?
Mendeleev
In terms of electron arrangement, explain why noble gases are unreactive
They have a full outer shell of electrons.
What are the elements in Group 0 called?
Noble gases
What charge do non-metal ions have?
Negative
Name the products produced when sodium reacts with: 1) Chlorine
2) Oxygen
3) Water
1) Sodium Chloride
2) Sodium Oxide
3) Sodium Hydroxide + Hydrogen
What happens to the melting and boiling points of Halogens as you go down the group?
Increase
What happens to the reactivity of the Halogens as you go down the group?
Decreases
What are the elements in Group 7 of the Periodic Table called?
Halogens
The discovery of what sub-atomic particle led to the plum pudding model of the atom?
The electron
How can a compound be seperated?
By a chemical reaction
Why might a scientist decide to change or replace an exisiting model?
New experimental evidence is put forward
Describe how you could use chromatography to identify a banned food dye in food colouring
1) Place food dyes on pencil line on chromatography paper
2) Place paper in solvent
3) Dye will dissolve in water and spread up paper
4) Colours in dye will seperate
5) Compare patterns of the food dyes with chromatogram of the banned food dye
What is the charge on an atom?
No overall charge
What relationship is there between the number of protons and electrons in an atom?
Number of protons equals the number of electrons
Who adapted the nuclear model of the atom by suggesting that electrons orbit at specific distances?
Niels Bohr
What are the relative charges of the particles in an atom?
1) Proton
2) Neutron
3) Electron
1) +1
2) 0
3) -1
What are the relative masses of the particles in an atom?
1) Proton
2) Neutron
3) Electron
1) 1
2) 1
3) Very small
What two conclusions about the atom were drawn from the results of the alpha particle scattering experiment?
1) The mass was concentrated at the centre (nucleus)
2) The nucleus was charged
What is the approximate size of the radius of an atom?
0.1 nm (1 x 10^-10^ m)
Approximately how many times smaller is the radius of the nucleus of the atom?
Radius of a nucleus is less than 1/10000 of that of the atom (over 10000 times smaller)
Who discovered the neutron about 20 years after the discovery of the nucleus?
James Chadwick
How do you calculate the mass number of an atom?
Mass number is the sum of protons and neutrons
What does the atomic number tell you about the particles in an atom?
Atomic number tells you the number of protons in an atom
Calculate the relative atomic mass of chlorine giventhe percentage abundances of the follien isotopes of Chlorine: 75% Chlorine-35 and 25% Chlorine-37
(75% x 35) + (25% x 37) = 35.5
Why is the table of elements called a ‘Periodic Table’?
Because elements with similar properties occur at regular intervals
How were elements in the early periodic table arranged?
By atomic weights
What charge do metal ions have?
Positive
Where are metals found on the Periodic Table?
Metals are on the left-hand side of the Periodic Table
Where are the non-metlas on the Periodic Table?
Non-metals are on the right-hand side of the Periodic Table
What is the name given to the elements in Group 1 of the Periodic Table?
Alkali Metals
What happens to the reactivity of alkali metlas as you go down the group?
Increases
How does the boiling point of noble gases change as you go down the group?
Increases
1) Name the type of reaction shown@
chlorine + sodium bromide - sodium chloride + bromine
2) What does this reaction tell you about the reactivity of chlorine and bromine?
1) Displacement reaction
2) Chlorine is more reactive than bromine
Which group of elements form molecules made up of pairs of atoms?
Halogens (group 7)
