<u>Answer:</u> The uncertainty in the velocity of oxygen molecule is 
<u>Explanation:</u>
The diameter of the molecule will be equal to the uncertainty in position.
The equation representing Heisenberg's uncertainty principle follows:

where,
= uncertainty in position = d = 
= uncertainty in momentum = 
m = mass of oxygen molecule = 
h = Planck's constant = 
Putting values in above equation, we get:

Hence, the uncertainty in the velocity of oxygen molecule is 
Answer:
B
Explanation:
Particles in a solid have fixed locations in a volume that does not change. Solids have a definite volume and shape because particles in a solid vibrate around fixed locations.
Answer:
Xenon is less reactive.
Explanation:
Xenon is a noble gas with 8 valence electrons whereas bromine is a halogen with 7 and is very reactive.
Answer:- C. 16.4 L
Solution:- The given balanced equation is:

From this equation, there is 2:1 mol ratio between HCl and hydrogen gas. First of all we calculate the moles of hydrogen gas from given grams of HCl using stoichiometry and then the volume of hydrogen gas could be calculated using ideal gas law equation, PV = nRT.
Molar mass of HCl = 1.008 + 35.45 = 36.458 gram per mol
The calculations are shown below:

= 
Now we will use ideal gas equation to calculate the volume.
n = 0.672 mol
T = 25 + 273 = 298 K
P = 101.3 kPa = 1 atm
R = 
PV = nRT
1(V) = (0.672)(0.0821)(298)
V = 16.4 L
From calculations, 16.4 L of hydrogen gas are formed and so the correct choice is C.