The answer will be A & B not only because it makes sense but evaporation is taking water away not adding to (gaining)
Answer : The density of an object is, 
Solution : Given,
Mass of an object = 60 g
Volume of an object = 
Formula used :

Now put all the given values in this formula, we get the density of an object.

Therefore, the density of an object is, 
A = mass number which is equal to the total number of protons + number of neutrons, Z= atomic number of any element which is also indicates Number of protons or number of electron in the given atom.
The formula to calculate neutron would be :
mass number - proton
31 - 15 = 16
Thus 16 neutrons are found in one atom of P
There are 4 atom in one molecule
Thus
4 atom /1 molecule * 9 molecule * 16 neutron / 1 atom
= 4*9*16= 576 neutrons
Answer:
The correct answer is 199.66 grams per mole.
Explanation:
Based on law of effusion given by Graham, a gas rate of effusion is contrariwise proportionate to the square root of molecular mass, that is, rate of effusion of gas is inversely proportional to the square root of mass. Therefore,
R1/R2 = √ M2/√ M1
Here rate is the rate of effusion of the gas expressed in terms of number of mole per uni time or volume, and M is the molecular mass of the gas.
Rate Q/Rate N2 = √M of N2/ √M of Q
The molecular mass of N2 or nitrogen gas is 28 grams per mole and M of Q is molecular mass of Q and based on the question Q needs 2.67 times more to effuse in comparison to nitrogen gas, therefore, rate of Q = rate of N2/2.67
Now putting the values we get,
rate of N2/2.67/rate of N2 = √28/ √M of Q
√M of Q = √ 28 × 2.67
M of Q = (√ 28 × 2.67)²
M of Q = 199.66 grams per mole
Answer:
the answer is 70.906 g/mol
Explanation: