Answer:
i would say the anwser is C
Answer:
frequency of light (f) = 1 x 10¹⁵s⁻¹
Explanation:
Given Data:
Wavelength of light λ = 3.0 x10⁻⁷m
Frequency of light: to be calculated
Formula Used to find frequency:
f = V/λ ........................... (1)
where
f is the frequency
V is the velocity
λ is wavelength
Velocity of light = 3 x 10⁸ ms⁻¹
put the values in equation (1)
f = 3 x 10⁸ ms⁻¹ / 3.0 x10⁻⁷m
f = 1 x 10¹⁵s⁻¹
So the frequency of light = 1 x 10¹⁵s⁻¹
The unit cm3 is used to express a cube using cm
Answer:
20.468 kilo Joules is the enthalpy change when one mole of sodium nitrate dissolves.
Explanation:
Heat lost by solution ad calorimeter = Q
Heat capacity of solution ad calorimeter = C = 1071 J/°C
Change in temperature = ΔT = 21.56°C - 25.00°C = -3.44°C


Heat gained by sodium nitrate = -Q = -(-3,684.24 J)=3,684.24 J
Moles of sodium nitrate = 
When 0.18 mole of sodium nitrate was dissolved in water 3,684.24 joulesof heat was absorbed by it.
Then heat absorbed by 1 mole of sodium nitrate :

1 J = 0.001 kJ
20.468 kilo Joules is the enthalpy change when one mole of sodium nitrate dissolves.