There are two possible situations.
1) If a phase change is not occurring, then the heat added contributes to increased translational energy of the particles. What that means is the particles move/vibrate faster.
2) If a phase change is occurring, then the heat added contributes to the breaking of bonds or intermolecular forces (depending on the chemical nature of the matter you're dealing with).
Answer: D
Explanation: others are solids and uranium is gas
According to Einstein the energy of photon is given by the equation,
E = hν = h . c/λ
where h is Planck's constant, c is the speed of light, ν is the frequency of light and λ is the wavelength of light.
Given, wavelength of photon = 413 nm = 413 x 10⁻⁹ m
Conversion factor: 1 nm = 10⁻⁹ m
c = 3 x 10⁸ m/s
h = 6.626× 10⁻³⁴ J.s
Substituting the data into the equation we get,
E = h . c/λ
E = 6.626× 10⁻³⁴ J.s x (3 x 10⁸ m/s) / 413 x 10⁻⁹ m
E = 4.8 x 10⁻¹⁹ J
The energy of this blue light is 4.8 x 10⁻¹⁹ J
Answer: C.It provides an alternative energy pathway for the reaction to proceed.
Explanation:
Activation energy is the extra energy that must be supplied to reactants in order to cross the energy barrier and thus convert to products.
A catalyst is a substance which increases the rate of a reaction by taking the reaction through a different path which involves lower activation energy and thus more molecules can cross the energy barrier and more molecules convert to products.
Thus catalyst speeds up the reaction and does not increase the total amount of product formed.
The catalyst itself does not take part in the chemical reaction and is regenerated as such at the end.
Answer:
A. boiling point
Explanation:
The correct answer is;
A. boiling point
The boiling point of a liquid is the temperature at which the vapour pressure is equal to the atmospheric pressure.
B. melting point
This option is wrong because the melting point is the temperature at which a solid undergoes a phase change to a liquid.
C. freezing point
This option is wrong because the freezing point is the temperature at which a liquid undergoes a phase change to a solid.
