Answer:
Average of measurements = 20.97 cm
Explanation:
Given data:
Three measurements of pete's = 20.9 cm, 21.0 cm, 21.0 cm.
Average value of measurements = ?
Formula:
Average of measurements = sum of all measurements / Total number of measurements
Solution:
Average of measurements = 20.9 cm + 21.0 cm + 21.0 cm. / 3
Average of measurements = 62.9 cm / 3
Average of measurements = 20.97 cm
Answer:
The answer is 1.15m.
Since molality is defined as moles of solute divided by kg of solvent, we need to calculated the moles of H2SO4 and the mass of the solvent, which I presume is water.
We can find the number of H2SO4 moles by using its molarity
C=nV→nH2SO4=C⋅VH2SO4=6.00molesL⋅48.0⋅10−3L=0.288
Since water has a density of 1.00kgL, the mass of solvent is
m=ρ⋅Vwater=1.00kgL⋅0.250L=0.250 kg
Therefore, molality is
m=nmass.solvent=0.288moles0.250kg=1.15m
Answer:
d and e - Sodium and antimony
Explanation:
The atomic numbers remain the same, while the mass numbers change (because neutrons are being added or taken away).
sodium has an atomic number of 19 and a mass number of 39 - in d, it has an atomic number of 19 but a mass number of 40. therefore, it is an isotope
antimony has an atomic number of 51 and a mass number of 121.60 - in e, it has an atomic number of 51, but a mass number of 123. therefore, it is an isotope
