atoms, ions, compounds

isotope

atoms of the same element has the same amount of protons, but different amount of neutrons

relative atomic mass (Ar)

weighted mean mass of an atom of an atom of carbon-12

relative formula mass

compares the mass of a formula unit with the mass of an atom of carbon-12

relative molecular mass (Mr)

compares the mass of a molecule with the mass of an atom of carbon-12

relative isotopic mass

mass of an isotope relative to 1/12 of the mass of an atom of carbon-12

carbon-12

international standard measurement of atomic masses

mathematical expression for Ar

(isotope abundance x isotope mass number) / sum of abundances of all the isotopes

mass spectrometry

a technique that separates particles according to their mass

polyatomic ion

an ion made of two or more atoms

ammonium

hydroxide

OH⁻

nitrate

NO₃⁻

carbonate

CO₃²⁻

sulfate

SO₄²

zinc ion

Zn²⁺

silver ion

Ag⁺

sulfide

S²⁻ (without oxygen)

sulfite

SO₃²⁻

hydrogen carbonate (bicarbonate)

HCO₃⁻

nitrite

NO₂⁻

blocks on PT

S (metals) D (transition) P (nmetals) F

relative charge of

protons

electrons

neutrons

protons : 1

electrons : 0

neutrons : 1

relative mass of

protons

electrons

neutrons

protons 1

electrons 1/1836

neutrons 1

cations and anions

cations : pawsitive ion (more E)

anions : negative ion (less E)

precipitate

an insoluble solid that forms from a solution during a chemical reaction, appearing as a solid cloud or settling to the bottom of the container