Nitrogen is a gas because it is an airlike fluid substance which expands freely to fill any space available, irrespective of it's quantity
Answer:
d) The dilution equation works because the number of moles remains the same.
Explanation:
Let’s say that you have 1 mol of a solute in I L of solution. The concentration is 1 mol·L⁻¹. and <em>M</em>₁<em>V</em>₁ = 1 mol.
Now, you dilute the solution to a volume of 2 L. You still have 1 mol of solute, but in 2 L of solution. The new concentration is 0.5 mol·L⁻¹.
The volume has doubled, but the volume has halved, and <em>M</em>₂<em>V</em>₂ = 1 mol.
b) <em>Wrong</em>. The molar concentration changes on dilution.
c) <em>Wrong</em>. The volume changes on dilution.
a) <em>Wrong</em>, although technically correct, because if the moles don’t change, the mass doesn’t change either. However, the formula <em>M</em>₁<em>V</em>₁ has units mol·L⁻¹ × L = mol. Thus, in the formula, it is moles that are constant.
Answer:
The edge of the length is 
Explanation:
From the given information:
The associated energy for a particle in three - dimensional box can be expressed as:
here;
h = planck's constant = 
= the quantum no in a specified direction
m = mass (of particle)
L = length of the box
At the ground state 
The energy at the ground state can be calculated by using the formula:
At first excited energy level, one of the quantum values will be 2 and the others will be 1.
Thus, the first excited energy will be: 2,1,1
∴
The transition energy needed to move from the ground to the excited state is:
----- (1)
Recall that:
the wavelength identified with the electronic transition is: 800 nm
800 nm = 8.0 × 10⁻⁷ m
However, the energy-related with the electronic transition is:
Replacing the value of 
in (1); then:
Making the edge length L the subject of the formula; we have:
Thus, the edge of the length is
Answer:
A = 0.023 m
Explanation:
The relation between the frequency of a radiation and its wavelength is given by the following expression.
where,
c is the speed of light (it has a constant value of 3.00 x 108 m/s)
A is the wavelength of the radiation v is the frequency of the radiation
In this case, the frequency is 13 GHz = 13 x
10° Hz = 13 x 1o° s-
The wavelength associated with this frequency is:
A = c/v = (3.00 x 10° m/s)/(13 x 10° s-") = 0.023
Answer:
Explanation:
A solid, at a given temperature, has a definite volume
and shape which may be affected by changes in
temperature. Solids usually increase slightly in size
when heated (expansion) and usually
decrease in size if cooled (contraction).A liquid, at a given temperature, has a
fixed volume and will take up the shape of any
container into which it is poured. Like a solid, a
liquid’s volume is slightly affected by changes in
temperature.
A gas, at a given temperature, has neither a definite
shape nor a definite volume. It will take up the shape
of any container into which it is placed and will
spread out evenly within it. Unlike those of solids
and liquids, the volumes of gases are affected quite
markedly by changes in temperature.
