Answer:
Explanation:
Precision relates to instruments of measurement or scale . A scale measuring upto cm is less precise than an instrument measuring upto mm .
Here the first measurement appears to have been taken with an instrument measuring up to metre and the second measurement appears to have been taken with an instrument measuring up to decimeter . So second measurement is most precise .
Third measurement is closest to the actual measurement that is 45.0 m , so it is most accurate measurement .
Answer:
-85 °C
Explanation:
O and S are in the same group( Group 16). Since S is below O it's atomic mass is higher than O. So molar mass of H2S is higher than H2O. The strength of Vanderwaal Interactions ( London dispersion forces) increases when the molar mass increases. However, only H2O can form H bonds with each other. This is because electronegativity of O is higher than S and therefore H in H2O has a higher partial positive charge than H of H2S.
H bond dominate among these 2 types of forces so the strength of attractions between molecules is higher in H2O than H2S. Therefore more energy should be supplied for H2O to break inter
molecular forces and convert from solid to liquid state than H2S. So mpt of H2O must be higher than that of H2S.
Aluminum Al2713 has an atomic molar mass of 27 grams per mole.
Al has 13 protons (hence number 13) and it most common isotope 14 neutrons for a total mass of 27 amu. ( The 13 electrons add no measurable mass to the atom)
Take the grams and divide by the molar mass
= 2 moles