Science, Chem - Material properties Flashcards
Atom
- everything is made up of atoms
- hundreds of different types of atoms
- smallest part of an element
- cannot be divisible
Elements
- something made of the same atom
- cannot be broken down into simpler substance
- represented by symbols
- have same properties as their atoms
Molecules
- atoms joining together to form larger particles
Compounds
- made of atoms of elements joined to atoms of other elements
- mixed/separated chemically
- can be broken down into simpler elements, using chemical reactions
- represented by the formula
- having different properties as their atoms
Mixture
mixed/separated physically
mono = ___
di = ___
tri = ___
tetra = ___
mono = one
di = two
tri = three
tetra = four
Compound, non-metal + metal
- metal
- nonmetal
- change ending of element to “-ide”
e.g. zinc + oxygen → zinc oxide
Compound, non-metal + metal + oxygen
- metal
- non-metal
- change ending of element to “-ate”
e.g. copper + sulphur + oxygen → copper
sulfate
Compound, ONLY non-metals
- depends on the amount of atoms
e.g. sulphur (1) + oxygen (2) → suphur
dioxide
Metal Oxide
- bases (pH more than 7)
- neutralize acid
- dissolve in water to form alkaline solutions
e.g. zinc oxide, calcium oxide, sodium oxide
Non - Metal Oxide
- most are acidic (pH less than 7)
- dissolve in water to form acidic solution
e.g. carbon dioxide, sulphur dioxide
Hydroxide
- compound of oxygen, hydrogen & another element
- some metal hydroxide dissolve in water to form alkaline solutions
Carbonates
compound of carbon, oxygen & another element
Sulfate
compound of sulfur, oxygen & another element
Chemical Reactions (1)
- happen everywhere
- to develop medicines, fuels & materials
- create new substances = will end up different
- are not reversible = can’t get back the substances you started with.
Chemical reactions (2)
- chemical atoms are rearranged to form new substances
- most reactions are irreversible
- substances & products - different chemical composition
- needs more energy
Physical change
- dissolving & changes of states are examples of physical changes
- most are reversible
- does not form a new substance
- properties and chemical composition remain the same
- needs less energy
Chemical reactions and Physical change
- occurs to matter
- needs energy
Change in properties
- color
- odor
- formation of bubbles
- formation of precipitate
Change in Energy
- warming + colour
- releases of light
Combustion
- burning
- type of chemical reaction
- reacts with oxygen
- produce light & heat energy
- needs; heat, fuel, oxygen
Corrosion
- metal reacts with oxygen to form metal oxide
- can be protective
Rust
- mixture of compounds
- formed when iron reacts with oxygen & water
- rusting = iron oxide
- prevent rust = paint, grease, oil, sacrificial metal.
Properties of Acids
- corrosive
- eat away metal, stone, flesh
- taste sour
- contains hydrogen
Properties of Bases & Alkalies
- soapy
- soluble bases
- able to burn skin
- contains hydroxide ions
- tastes bitter
Neutralization
- acid + alkali form salt + water
- hydrochloric acid = produce chloride
- sulphuric acid = produce sulphate
- nitric acid = produce nitrates
- ethanoic acid = produce ethanoates
Solute
- thing that dissolves (e.g. salt)
Solvent
- thing that dissolves it (e.g. water)
Solution
- product of solute and solvent (e.g. saltwater)
Separation techniques
- Distillation
- Fractional distillation
- Evaporating
- Condensing
- Filteration
