<span>E = ħc / λ
ħ = plancks constant = 6.626x10^-34 Js
c = speed of light = 2.999x10^8 m/s
λ = wavelength of light = 670.8x10^-9 m
E = (6.626x10^-34 Js) x (2.999x10^8 m/s) x (1 / 670.8x10^-9 m)
E = 2.962x10^-19 J
</span><span>3x10^8 / (670.8 * 10^-9)
=4.47x10^14 Hz
4.47x10^14 Hz multiplied by plank's constant = 2.9634x10^-19
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M = 4.79 kg = 4790 g
d = 7.86 g/cm3
density = mass/volume
v = m/d
v = 4790/7.86
v = 609.4 cm3
1 cm3 = 10^-2 dL
v = 609.4 x 0.01 = 6.09 dL
A closed system is completely closed to the outside environment. Every interaction is transmitted inside that closed system.
Answer:
a. Heat is often absorbed during reactions.
c. Heat is often released during chemical reactions.
Explanation:
Thermochemistry -
The study of thermochemistry involve the change in the amount of heat , during any physical or chemical process , is referred to as thermodynamics .
The focus of thermochemistry is on the changing amount of energy in the form of heat , on the system with respect to the surroundings .
The process like boiling , melting , sublimation , may require energy or releases energy , and hence are studied under thermochemistry .
Hence , from the given question ,
The correct options are - a , c.