elements & substances ( form 4 chap 8 ) Flashcards
what are atoms?
atoms are the smallest particles of any element.
consist of only atomic particles.
metal is an element formed from atoms.
what are molecules?
molecules are made up of 2 or more atoms of the same type or different.
what are ions?
ions are substances formed through the reaction of metal and non-metal atoms.
an example of atoms?
copper / iron / zinc / lead
an example of molecules?
oxygen / water / ammonia / nitrogen
an example of ions?
sodium chloride ( salt )
how are elements on the modern periodic table arranged?
according to their groups ( vertical ) and periods ( horizontal ) and increasing of protons
what is a duplet?
when the first shell consists of its maximum amount which is 2 electrons
how do you get a stable electron arrangement?
by donating valence electrons ( positive ion ) / accepting valence electrons ( negative ion ) to create an octet
what is an isotope?
isotopes are elements with the same number of protons but different number of neutrons.
what isotope is used to estimate the age of fossil and ancient artefacts?
carbon - 14
what isotope is used to detect leakage in underground pipelines?
sodium - 24
what is phosphorus - 32 used for?
to study the absorption rate of plants containing phosphorus fertiliser.
what is the use of cobalt - 60?
to kill cancer cells with gamma rays
what isotope is used to treat thyroid gland disorders?
iodine - 131
