Atomic structure and the periodic table (1) Flashcards
what is a compound?
A substance that contains two or more elements that are chemically combined.
Who created the periodic table?
Dimitri Mendeleev
What are ions?
An atom that has lost or gained an electron.
What is the subscript when an atom loses an electron?
+
What is the subscript when an atom gains an electron
-
What are reactants?
substances that react together in a chemical reaction
What are the four state symbols?
Solid (S) Liquid (L) Gas (G) Aqueous solution (aq)
What is H20(S)
Ice
What is HCL(G)
Hydrogen Chloride gas
What is the law of the conversation of mass?
No atoms are lost or made during a chemical reaction
N2 + H2 = NH3
Is this a balanced equation?
No
What is a pure substance?
A substance consisting of only one element or compound
What is a mixture?
two or more different substances, not chemically joined together
True or false
the components of a mixture can be separated without chemical reactions
True
What is filtration?
separating an insoluble solid from a liquid
What is crystallisation?
what is simple distillation?
Separating a solvent from a solution
Producing pure water from seawater e.g
What is fractional distillation?
Separating different liquids from a mixture of liquids
What is paper chromatography?
Separating mixtures of soluble substances
Who discovered the electron?
J J Thomson
What is the plum pudding model of an atom?
A ball of positive charge with negative electrons embedded within
Who performed the gold foil experiment?
Rutherford
Who created the nuclear model for an atom?
Rutherford
What did the gold foil experiment prove?
There was space within the atom
There is a positive nucleus within
Who discovered that electrons orbit the nucleus in shells?
Bohr
Who discovered neutrons within the nucleus?
Chadwick
What is the radius of an atom?
0.1nm / 1x10 (to the power of)-10 m
what is the radius of a nucleus?
1 x 10 (to the power of) -14 m
what is the relative charge of a proton, a neutron, and an electron?
+1, 0, -1
what is the atomic number of an element?
The number of protons in it
It is always the smallest number
how do you work out the number of neutrons in an element?
mass-atomic
what are isotopes?
Atoms of the same element with a different number of neutrons
different mass numbers
What is the relative atomic mass of an atom?
a weighted average of the masses of the atoms of the isotopes.
What is the formula to calculate the relative atomic mass?
The total mass of atoms / total number of atoms
Why did Mendeleev leave gaps in the periodic table?
- For undiscovered elements
- To predict the properties of undiscovered elements
what is the electric structure of an atom?
the way electrons are arranged in an atom
properties of metals
Good conductor of electricity Good conductor of heat Shiny High density Malleable Ductile
properties of non metals (when solid)
Good conductor of electricity Poor conductor of electricity Poor conductor of heat Dull Low density Brittle
what are the elements in group 0 known as
noble gases
what common properties do all noble gases share
low boiling points
what happens as you go down group 0
- the atoms become larger
- intermolecular forces between atoms become stronger
- more energy is needed to overcome these forces
