Explanation:
Calcium carbonate is a molecule that contains one atom of calcium, one atom of carbon, and three atoms of oxygen.
Answer : The energy of one photon of hydrogen atom is, 
Explanation :
First we have to calculate the wavelength of hydrogen atom.
Using Rydberg's Equation:

Where,
= Wavelength of radiation
= Rydberg's Constant = 10973731.6 m⁻¹
= Higher energy level = 3
= Lower energy level = 2
Putting the values, in above equation, we get:


Now we have to calculate the energy.

where,
h = Planck's constant = 
c = speed of light = 
= wavelength = 
Putting the values, in this formula, we get:


Therefore, the energy of one photon of hydrogen atom is, 
Answer:
total surface area is 432
Explanation:
Given data
base = 6
diagonals = 8
altitude = 12
to find out
total surface area
solution
we know total surface area of prism is
total surface area = lateral surface area + 2base area ..............1
so
first we calculate base perimeter i.e = 2 length + 2 width
so perimeter = 2(8) + 2(6) = 25
and area = length * width = 8*6 = 48
so lateral surface area is perimeter * height i.e
lateral surface area = 28* 12
lateral surface area = 336
put this value in equation 1 we get
total surface area = lateral surface area + 2base area
total surface area = 336 + 2(48)
total surface area is 432
W = _|....F*dx*cos(a)........With F=force, x=distance over which force acts on object,
.......0.............................and a=angle between force and direction of travel.
Since the force is constant in this case we don't need the equation to be an integral expression, and since the force in question - the force of friction - is always precisely opposite the direction of travel (which makes (a) equal to 180 deg, and cos(a) equal to -1) the equation can be rewritted like so:
W = F*x*(-1) ............ or ............. W = -F*x
The force of friction is given by the equation: Ffriction = Fnormal*(coeff of friction)
Also, note that the total work is the sum of all 45 passes by the sandpaper. So our final equation, when Ffriction is substituted, is:
W = (-45)(Fnormal)(coeff of friction)(distance)
W = (-45)...(1.8N).........(0.92).........(0.15m)
W = ................-11.178 Joules