05 Atoms Flashcards
The Universe
- All of space and time
- Made up of matter and energy
Matter
- All of the physical substances around us
- Anything that has mass and takes up space
Atoms
- The extremely small unit that elements are made of
- Cannot be chemically broken down into smaller particles
Sub-Atomic particles
- The tiny particles that an atom is made of
- Smaller than atoms
An element
Matter made up of the same type of atoms
The table in which all elements are arranged
Periodic table
The element: H
Hydrogen
The element: He
Helium
The element: Li
Lithium
The element: Be
Beryllium
The element: B
Boron
The element: C
Carbon
The element: N
Nitrogen
The element: O
Oxygen
The element: F
Fluorine
The element: Ne
Neon
The element: Na
Sodium
The element: Mg
Magnesium
The element: Al
Aluminium
The element: Si
Silicon
The element: P
Phosphorus
The element: S
Sulfur
The element: Cl
Chlorine
The element: Ar
Argon
The element: K
Potassium
The element: Ca
Calcium
The element: Ti
Titanium
The element: Cr
Chromium
The element: Mn
Manganese
The element: Fe
Iron
The element: Ni
Nickel
The element: Cu
Copper
The element: Zn
Zinc
The element: Br
Bromine
The element: Ag
Silver
The element: Sn
Tin
The element: I
Iodine
The element: Pt
Platinum
The element: Au
Gold
The element: Hg
Mercury
The element: Pb
Lead
The element: U
Uranium
Models in science:
- A model is a representation of a system in the real world.
- Models help us to understand systems and their properties.
The atom model represented by this diagram:

Dalton’s ‘billiard ball’
(1807)
The atom model represented by this diagram:

Schrödinger’s ‘electron clouds’
(1926)
The atom model represented by this diagram:

Thompson’s ‘plum pudding’
(1904)
The atom model represented by this diagram:

Rutherfords ‘solar system’
(1911)
The atom model represented by this diagram:

Bohr’s ‘electron orbit energy levels’
(1913)
The three main subatomic particles
- Protons
- Neutrons
- Electrons
How to determine the number of protons?
The same number as the atomic number
How to determine the number of electrons?
Same number as the number of protons
How to determine the number of neutrons?
The difference between the atomic mass and the atomic number.
Number of protons, neutrons and electrons in Sodium:

Protons: 11
Neutrons: 12
Electrons: 11
The number of protons, neutrons and electrons in Fluorine:

Protons: 9
Neutrons: 10
Electrons: 9
The number of protons, neutrons and electrons in Carbon:

Protons: 6
Neutrons: 6
Electrons: 6
A molecule
Two or more atoms that are chemically bonded (joined) together
Compounds
Matter made up of two or more different elements chemically bonded together
Is a bar of gold an example of an element or a compound?
Element
Is oxygen gas and example of an element or a compound?
Element
Is water an example of an element or a compound?
Compound
Is sodium chloride (table salt) an example of an element or a compound?
Compound
Can elements exist as molecules but not be compounds?
Yes
E.g. diatomic molecules of hydrogen, oxygen, and chlorine

Mixtures
- Matter consisting of two or more different types of particles (different elements or compounds)
- In varying amounts
- Physically mixed together
Pure substances
Matter made up of only one type of atom or molecule.
Chemical bonds
- Strong forces of attraction that hold atoms together in a molecule
- These are broken and formed between different atoms during chemical reactions
Electrolysis
Chemical decomposition reaction by passing an electrical current through a liquid solution
Decomposition of water results in:
Hydrogen gas (bubbles)
Oxygen gas (bubbles)
Chemical decomposition of copper chloride results in:
- Copper (solid coating the -ve electrode)
- Chlorine (gas bubbles at the +ve electrode)
Thermal chemical decomposition
Using thermal energy (e.g. a flame) to chemically decompose a compound
Thermal decomposition of potassium permanganate results in what gas being released?
Oxygen
The positive test for the presence of oxygen gas
A glowing splint ignites and has a flame
Example methods of separating mixtures
sorting
sifting
using a magnet
dissolving
evaporating e.g. distillation
What property of water and ethanol allow for distillation to work as a method of separating a mixture of water and ethanol?
- Water has a higher boiling point (temperature) than ethanol.
- If you heat the mixture up, most of the ethanol will form a vapour before the water.
Electrons
Negatively charged subatomic particles spinning around the nucleus of an atom
Neutrons
Neutral subatomic particles found in the nucleus of an atom
Protons
Positively charged subatomic particles found in the nucleus of an atom
Example properties of substances
- Phase (solid, liquid or gas?)
- Conductivity (conducts electricity?)
- Solubility (soluble in water?)
- Density (amount of mass in a given volume?)
- Magnetism (is it magnetic?)
- Melting point (what temperature causes it to melt?)
- Boiling point (the temperature that it boils?)
Example diatomic elements
- Hydrogen
- Nitrogen
- Oxygen
- Fluorine
- Chlorine
- Bromine
- Iodine