1 mole=6.02 x 10^23 atoms so how many moles are there in 3.0 x 10^23 we will cross multiply, 1 x 3.0 x 10^23 / 6.02 x 10 ^23. Which will give us 0.498 moles.
Hope this helped
Answer:
D
Explanation:
D is the answer because 2 is needed to know
Answer and Explanation:deposition has been occurring on earth for a very long time. as time goes by, more deposits form layers on the earth, including the remains of animals and plants that would later become fossils, burying the previous deposits in another layer of newer deposits. therefore it follows that layers which are found deeper are older than those found in layers near the surface....
hope it helps u..
Answer:
MOLAR MASS = 32 g/mol
Explanation:
Condition of standard temperature and pressure(STP) are as follow:
Temperature = 273 K
Pressure = 1 atm (or 100000 Pa)
Here atm is atmosphere and Pa is Pascal
STP conditions arte used for measuring gas density and volume using Ideal Gas Law.Here 1 mole of ideal gas occupies 22.4 L of volume.
According toi Ideal Gas Equation :
PV = nRT
where P = pressure, n= number of moles, V = volume ,R= Ideal Gas Constant and T= temperature

From question:
V=280 ml = 0.28 L
P = 1 atm
R=0.08205 L atm/K mol
T=273 K
Putting values in above formula :

n = 0.0125 moles
Now 

given mass = 0.4 g (given)

On solving we get:
Molar mass = 32 g/mol