Chapter 1 - Materials Flashcards
(37 cards)
Neutron charge, mass, location
Neutral, 1, nucleus
Electron charge, mass, location
Negative, 0, orbiting in shells
Atomic Number
Number of protons
Atomic mass
Number of protons and neutrons
Electron shell numbers
1st: 2, next two shells: 8
Metal properties
Ductile, lustrous, malleable, conductive, solid (except mercury)
Non-Metal properties
Dull, brittle, poor conductors, usually a liquid or gas
Pure metals
A metal in its purest form, made of only 1 element and is soft. Eg: Aluminium
Alloys definition
An impure substance of a mix of two or more metals. Eg: brass is an alloy made from copper and zinc. It’s used to make money and musical instruments
Advantages of alloys
Alloys are usually an improvement from their base metal as metals in their purest form can be too soft and easy to break, therefore, mixing the, with other elements stringer and more durable metals
Bronze properties and uses
95% Cu, 5% Zn used for statutes, ornaments and bells. Properties: looks good, sonorous (rings when struck), harder than brass, stronger than copper
Duralumin properties and uses
96% Al, 4% Cu, traces of Mg and Mn. Used for aircraft frames. Properties: very light, stronger than its base metal (aluminium)
Cupronickel
75% Cu, 25% Ni. Used for silver coins (5,10,20 and 50 cents). Properties: hard wearing, looks like silver
What is an acid?
A substance that releases hydrogen ions into an aqueous solution (containing water). Eg: hydrochloric acid in your stomach, ethanoic acid in vinegar
Properties of acids
Corrosive, sour taste, turns blue litmus paper red, reacts with some metals releasing hydrogen and leaving salt behind, conduct electricity, neutralised by bases, producing water and salt
Polyatomic Ion
An ion which is a charged group of atoms eg hydroxide
What is a base
A substance that releases hydroxide ions and if it can be dissolved in water than it is an alkali
Properties of Bases
Caustic, have a soapy/slimy feel, turn red litmus paper blue, have a bitter taste, conduct electricity, are neutralised by acids producing water and salt
pH
pH is a measure of acidity and alkalinity. If the substance is more acidic there are more hydrogen ions and if it is an alkaline solution it has more hydroxide ions. Pure water is in the middle so has equal amounts of hydrogen and hydroxide ions and has a pH of 7 on the scale of 1-14
Proton charge, mass, location
Positive, 1, located in the nucleus
Democritus
460 BC, matter is made of ‘indivisible’ particles. Extremely small solid particles make up everything. Solid Sphere as model (one of the perfect shapes
Dalton
1808, refined democritus’ theory. Made a list of the known elements and calculated weights and properties. (Same model as Democritus)
J.J Thompson
-1903. After discovery of electrons, proposed plum pudding model. Positively charged pudding embedding with negatively charged electrons
Rutherford
- Gold foil experiment. Small dense nucleus with electrons orbiting like planets. Solar system model, planetary model. Majority of atom empty space