It's very simple.
Energy =

where, h= Planck's constant = 6.6 x

c= speed of light = 3 x

m/s

= wavelength
So, energy =

= 1.65 x

J
=1.65 x

KJ
Answer:
she can use crystalization method.
Explanation:
She should boil that liquid on flame and then cool it down on mederate temprature and check it out rather the crystals formed or not . if crystals are formed then there will be salts.
And if she want topredict the certain salt then she has to perform certain reactions.
Answer:
The answer is 4.
Explanation:
Take trail mix as a mixture. It can easily be separated by hand. Take sugar in hot coca as a solution. You cannot separate sugar from the hot coca with your hands.
From the statement of Hess' law, the enthalpy of the reaction A---> C is +90 kJ
<h3>What is Hess' law?</h3>
Hess' law of constant heat summation states that for a multistep reaction, the standard enthalpy of reaction is always constant and is independent of the pathway or intermediate routes taken.
From Hess' law, the enthalpy change for the reaction A ----> C is calculated as follows:
A---> C = A ---> B + B ---> C
ΔH of A---> C = 30 kJ + 60 kJ
ΔH = 90 kJ
Therefore, the enthalpy of the reaction A---> C is +90 kJ
The above reaction A---> C can be shown in the enthalpy diagram below:
A -------------------> C (ΔH = +90 kJ)
\ /
\ / (ΔH = +60 kJ)
(ΔH = +30 J) \ /
> B
Learn more about enthalpy and Hess law at: brainly.com/question/9328637
Answer:
a molecule
Explanation:
A molecule is the smallest unit quantity of a compound which can exist by itself and retain ALL the properties of the original substance.
Hope that helps
have a good day
can i have brain pls