IGCSE Chemisty - Topic 1 Flashcards
What’s an atom?
The smallest particle of an element
Proton Mass
1 amu
Neutron Mass
1 amu
Electron Mass
1/1837 (Approx 0 amu)
Proton Charge
+1 (Positive Charge)
Neutron Charge
0
Electron Charge
-1 (Negative Charge)
Atomic Number
The number of protons in the nucleus of the atom
Mass number
The total number of protons and neutrons in the nucleus of the atom
Isotopes
Atoms of the same element with the same number of protons but a different number of neutrons
Element
A pure substance made of only one kind of atom
Chromatography
A technique that is used to separate components of a mixture
Solute
The substance which dissolves in a liquid to form a solution
Soluble
Describes a substance that will dissolve
Solvent
The liquid in which a solute dissolves in
Solution
The mixture formed when a solute is dissolved in a solvent
In-soluble
Describes a substance that will not dissolve
Solubility
Describes the ability/likelihood of a solute to dissolve in a solvent
Brownian motion
The random movement of particles in liquids and gases
What are the two types of isotopes?
Radioactive (Unstable) and Non-radioactive (Stable
Compounds
A substance made up of atoms of two or more different chemically combined elements
Mixture
A combination of two or more substances that are not chemically combined
Alloy
An alloy is a mixture of two or more elements, where at least one element is a metal.
Ions
Atoms or groups of atoms with a positive or negative charge
Diffusion
Movement of particles from an area of higher concentration to an area of lower concentration
Formula for Rf (Reference front) value
Distance travelled by substance/distance travelled by solvent
Describe Solid
Close together and touching, regular arrangement (lattice), fixed shape and volume, can not freely move but does vibrate, can not be compressed and does not diffuse
Describe Liquid
Touching, irregular arrangement, can freely move/slide over each other, force of attraction holds them together, fixed volume but no fixed shape, can not be compressed, slow diffusion
Describe Gas
Far apart, irregular, can freely move in a random and independent manner, very small or no force of attraction, no fixed shape, no fixed volume but can fit in a container, easily compressed, rapid diffusion
