4X + 3O₂ = 2X₂O₃
n(X₂O₃)=0.02225 mol
m(X)=4.000 g
x - the molar mass of metal
m(X)/4x=n(X₂O₃)/2
x=m(X)/{2n(X₂O₃)}
x=4.000/{2*0.02225)=89.89 g/mol
X=Y (yttrium)
To correct her measurement to standard temperature and pressure (STP), she must <span>make a volume correction based on a higher temperature of 273 K. The answer is letter B. This is in order to correct the temperature and pressure because correcting the volume will indicate that the temperature and pressure will result to the opposite result of the volume. This is because volume is indirectly proportional with pressure and temperature.</span>
Explanation:
about 78 % of the air is nitrogen and 21% is oxygen . These two gases can be seperated by fractional distillated of liquid air . Air is filtered to remove dust ,and then cooled in states until it reaches -200'C at this tempereture it is liquid . The air has been liquefied. And after a distillation process you can obtain nitrogen from a mixture of nitrogen and oxygen .
Answer:
The answer is C
Explanation:
Because i know look at my grade.
Answer:
The half-life is
Explanation:
From the question we are told that
The sample is 90 Y
The first activity is per minute
The second activity is per minute
The duration from 1:00 p.m. on December 3, 2006 to 2:15 p.m. on December 17, 2006 is
Converting to minutes we have
The first order rate constant for this disintegrations can be mathematically represented as
Where is the rate constant
Substituting values
So
The half life is mathematically represented as
So