C1 - Atomic Structure and The Periodic Table Flashcards
What is an element?
A substance containing only 1 type of atom. e.g Mg, O2, Cl2
What is a compound?
A substance containing two or more different types of atoms CHEMICALLY BONDED. e.g. H20
What is conservation of mass?
Atoms can neither be created or destroyed in a chemical equation - both sides must be balanced
What is a mixture?
Combination of two or more substances that are not chemically joined together. e.g. air, solutions
What is FILTRATION?
Removing large, insoluble molecules from a liquid. e.g. sand from water
What is CRYSTALLISATION (evaporation)?
Evaporating the solvent from a solution to leave a solute (dissolved substance) behind.
e.g. salt from water
What is DISTILLATION?
Heating a solution to separate the solvent and solute, and then cooling the evaporated gas of the solvent and condensing it to collect the liquid.
What is FRACTIONAL DISTILLATION?
Separating liquids due to their different boiling points
What is CHROMATOGRAPHY?
A technique used to separate different components within a mixture.
What are the three states of matter?
Solid (S), Liquid (L), Gas (G)
What does (Aq) mean?
Aqueous - dissolved in solution
What is the process by which a solid becomes a liquid?
Melting
What is the process by which a liquid becomes a gas?
Evaporation/boiling
What is the process by which a solid goes straight to a gas? (Skips out liquid)
Sublimation
What is the process by which a gas turns into a liquid?
Condensation
What is the process by which a liquid turns into a solid?
Freezing/Solidification
Characteristics of a solid
-particles in a regular/fixed arrangement (lattice) and vibrate about fixed positions
-cannot be compressed
Characteristics of a liquid
-particles have no regular arrangement and are able to move past each other
-cannot be compressed
Characteristics of a gas
-particles are far apart, move randomly at fast speeds (high energy)
-can be compressed
What is overcome during evaporation and melting?
Electrostatic forces
Order of discovery for the proton, neutron and electron
1st: Electron
2nd: Proton
3rd: Neutron
Order of discovery for the proton, neutron and electron
1st: Electron
2nd: Proton
3rd: Neutron
What did John Dalton do?
Popularised the theory that matter is made up of invisible particles (atoms)
What did JJ Thompson discover?
Atoms are made up of positive and negative charges - Proton and electron
Who made the plum pudding model and what is it?
JJ Thomson - A positive charge with lots of little negatively charged electrons dotted around it
What did Ernest Rutherford discover?
Positively charged Nucleus
Who carried out the alpha particle scattering experiment and what was it?
Ernest Rutherford - He shot alpha particles at a golden ‘leaf’, most of which went through showing the atom was mostly empty space, but some deflected back, showing the nucleus was in the centre
What did Niels Bohr discover?
That electrons orbit the nucleus in shells
What did James Chadwick discover?
Neutron
Relative charge of a proton
+1
Relative mass of a proton
1
Relative charge of a neutron
0
Relative mass of a neutron
1
Relative charge of an electron
-1
Relative mass of an electron
0 (very small)
What is the bottom number in the periodic table and what does it show?
Atomic number - number of protons ( and electrons- they are the same to cause a neutral charge)
What is the top number in the periodic table and what does it tell us?
Mass number - the number of protons + neutrons
What is an atom called if it does not have a neutral charge?
An Ion
What is an isotope?
The same element, but with a different number of neutrons
How to calculate average mass of two or more isotopes?
Total mass of 100 atoms
Average mass = ————————-
100
How were the elements arranged before the periodic table?
By atomic weight, however some were grouped together if they were seen to have similar properties.
What did Dimitri Mendeleev do to the periodic table?
Ordered them in terms of chemical properties
Dimitri found gaps in his table, how was he proven correct over time?
Elements were found, and they fitted into the gaps
How many electrons are in the 1st, 2nd, 3rd and 4th shell
1st = 2
2nd = 8
3rd = 8
4th = 2
Electron configuration for Magnesium (12 electrons)
2,8,2
Do metals lost or gain electrons to form a full/empty outer shell? Do they form positive or negative ions?
Lose and positive ions
Do non-metals gain or lose electrons to form a full outer shell? Do they form positive or negative ions?
Gain and negative ions
What does the group number of the periodic table represent?
Number of electrons in outer shell of atom
What are group 1 metals known as?
The Alkali Metals
Do alkali metals get more or less reactive the further down the group you go?
More - easier to lose 1 electron as further away from nucleus so electrostatic force is weaker
What are group 7 elements known as?
The halogens
Do halogens get more or less reactive as you go down the group?
Less - further away from nucleus, so harder to attract one more electron
Does boiling point increase or decrease as you go down group 7 (the halogens)
Decrease
How reactive are the noble gases (group 0/8 elements)?
Very unreactive
Properties of transition metals
-Hard
-less reactive than the alkali metal
- form coloured compounds
