Answer:
dont know how to remove the answer read it wrong
Because they're not confident enough to confirm it's indeed true but they will support it for they believe it's correct.
Answer: There are 
atoms of hydrogen are present in 40g of urea, 
.
Explanation:
Given: Mass of urea = 40 g
Number of moles is the mass of substance divided by its molar mass.
First, moles of urea (molar mass = 60 g/mol) are calculated as follows.
According to the mole concept, 1 mole of every substance contains 
atoms.
So, the number of atoms present in 0.67 moles are as follows.
In a molecule of urea there are 4 hydrogen atoms. Hence, number of hydrogen atoms present in 40 g of urea is as follows.
Thus, we can conclude that there are atoms of hydrogen are present in 40g of urea, .
It is melting point process
The mass of air in the scuba tank is 841.614 g.
Using the ideal gas equation;
PV=nRT
P = pressure of the gas = 195 kPa
V = volume of the gas = 350 L
n = Number of moles of the gas = ??
R = molar gas constant = R = 8.314 J K-1 mol-1
T = temperature of the gas = 10 °C or 283 K
n = PV/RT
n = 195 * 350/8.314 * 283
n = 68250/2352.862
n = 29.00 moles
Number of moles = mass/molar mass
mass of air = Number of moles * molar mass
mass of air = 29.00 moles * 29g/mol
Mass of air = 841.614 g
Learn more: brainly.com/question/4147359
