Chemistry Test Flashcards
combustion reaction
substance + O2 > product + H2O (g)
neutralisation
acid + base > salt (acid a, base c) + water
decomposition
one reactant > 2 products
e.g. H2CO3 > H2O + CO2
combination
2 reactants > 1 product
e.g. 2H2 + O2 > 2H2O
precipitation
(aq) + (aq) > (aq) + [(aq) or (s)]
corrosion
metal + O2 + H2O > metal oxide (e.g. rust)
acids + metal
acid + metal > salt + H2
acid + carbonate
acid + metal carbonate > salt + H2O + CO2
exothermic reaction
releases energy (hot) e.g. fireworks, explosions, bunsen burners
endothermic reaction
absorbs energy (cold) e.g. cold packs
carbon dioxide
CO2
hydrochloric acid
HCL
sulfuric acid
H2SO4
nitric acid
HNO3
sodium hydroxide
NaOH
aqueous (aq)
dissolves in water (solution)
conservation of mass
during a chemical equation, atoms cannot be created nor destroyed
acids
substances which ionize in water to produce H+ ions
strong vs weak acids
strong - acids produce lots of H+ ions
weak - acids produce not many H+ ions
bases
substances which produce OH- ions
strong vs weak bases
strong - bases produce lots OH- ions
weak - produce not not many OH- ions
PH scale
measures concentration of H+ ions from 0-14
acidic - PH less than 7
neutral - PH of 7
basic - PH more than 7
indicator
substances that change colours at different PHs
- determines approx PH of solutions
litmus
indicator
- acidic = red
- basic = blue
nuclear decay
the nucleus of an atom releases energy or particles
types of nuclear decay
- alpha (α)
- beta (β)
- gamma (γ)
alpha decay
- atom emits alpha particle (2p, 2n) from its nucleus
- heavy and slow
beta decay
- atom ejects a beta particle (an electron) from its nucleus
- very light and high-speed
- turns neutron into proton > changes element
gamma decay
- atom does not eject a particle, ejects a very high energy form of light
- very dangerous and powerful
electromagnetic radiation scale
low radiation -> high radiation
nuclear charge table
alpha: +2
beta: -1
gamma: 0
half life
- the rate that a radioisotope undergoes nuclear decay
- time taken for half of the radioactive atoms to decay