1. Atomic Structure Flashcards
Substances are all made of tiny particles, these are called…
Atoms
Substances made of only one type of atom are called…
Elements
All of the symbols for elements are arranged and displayed on the…
Periodic Table
The columns in the periodic table are called…
Groups
On the left of the periodic table are…
Metals
On the right of the periodic table are…
Non-Metals
The structure of an atom is…
A central nucleus with electrons orbiting it in shells
Compounds contain…
More than one type of atom
Chemical equations show…
The reactants (what you start with) and products (what you end up with)
CaCO3 —> CaO + CO2 is an example of…
A balanced symbol equation showing calcium carbonate decomposing
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 are state symbols?
State symbols give extra information about the equation, they include (s), (l), (g), and (aq)
How would you balance the equation H2 + O2 —> H2O?
2H2 + O2 —> 2H2O
In a chemical reaction, atoms are never…
created or destroyed
What is a mixture?
Something made up of two or more substances that are not chemically combined together
Mixtures can be separated by physical means such as…
filtration, crystallisation and simple distillation
What is fractional distillation?
An effective way of separating miscible liquids using a fractionating column
What makes fractional distillation possible?
The different boiling points of liquids in a mixture
What is paper chromatography?
A way of separating mixtures of substances by using a solvent
What makes paper chromatography possible?
The different solubilities of the substances in the solvent
How did John Dalton describe an atom in the 1800s?
A tiny hard sphere that could not be split or divided
What did J.J. Thomson discover?
The electron
What was Thomson’s ‘Plum Pudding’ model of the atom?
A cloud of positive charge with negative electrons embedded within it
Which scientists conducted the alpha particle experiment that changed the plum pudding model?
Geiger and Marsden
Who proposed the existence of the nucleus of an atom and therefore created a new model of the atom?
Rutherford
Who discovered electron shells?
Niels Bohr
Who discovered neutrons in 1932?
James Chadwick
What is the relative charge of a proton?
+1 (positive)
What is the relative charge of an electron?
-1 (negative)
What is the relative charge of a neutron?
0 (neutral)
What is the relative mass of a proton?
1
What is the relative mass of an electron?
very small, almost 0
What is the relative mass of a neutron?
1
The atomic number of an atom is the…
number of protons in the atom, this is the same as the number of electrons
The mass number of an atom is the…
number of protons + the number of neutrons
How is an ion created?
When an atom gains or loses an electron
What is an isotope?
Atoms of the same element with different numbers of neutrons
How many electrons does the electron shell closest to the nucleus hold?
2
How many electrons does the other electron shells of an atom hold?
8
The number of electrons in the outer shell of an atom…
determines the way in which that element will react and is the same as the Group it is in on the periodic table.
