81. There is 1 carbon, 2 chlorine and fluorine atoms in Freon 12. To draw them it forms a cross with C in the middle and Cl and F both on the opposite side.
Cl
l
F - C- F
l
Cl
82. Freon-12 and Freon-14 are called halocarbons or just halides.
Answer:- Frequency is
.
Solution:- frequency and wavelength are inversely proportional to each other and the equation used is:

where,
is frequency, c is speed of light and
is the wavelength.
Speed of light is
.
We need to convert the wavelength from nm to m.
(
)

= 
Now, let's plug in the values in the equation to calculate the frequency:

=
or 
since, 
So, the frequency of the green light photon is
.
Kinetic energy of the molecules increases and we are close to boiling point liquids. Then strain the liquid and gas pressure reached equilibrium
.
1) is right
2) lead(ii) phosphate
3) iron(iii)sulfate
4) lead(ii)oxide
5) lead sulfate
6) copper iodide
7) lead oxide
Answer:
When an organism dies, it is usually destroyed by other forms of life and by weathering processes. On rare occasions some body parts—particularly hard ones such as shells, teeth, or bones—are preserved by being buried in mud or protected in some other way from predators and weather. Eventually, they may become petrified and preserved indefinitely with the rocks in which they are embedded. Methods such as radiometric dating—measuring the amounts of natural radioactive atoms that remain in certain minerals to determine the elapsed time since they were constituted—make it possible to estimate the time period when the rocks, and the fossils associated with them.