Answer:
The temperature will decrease (get colder).
Explanation:
Enthalpy changes are heat changes accompanying physical and chemical changes. The enthalpy change is the difference between the sum of the heat contents of products and the sum of heat contents of reactants.
- For an endothermic change, heat is absorbed for the reaction.
- The surrounding becomes colder at the end of the reaction and so is the reaction itself.
- The right choice is that the temperature will decrease.
Answer:
Friction
Explanation:
Friction is a force that slows down moving objects. If you roll a ball across a shaggy rug, you can see that there are lumps and bumps in the rug that make the ball slow down. The rubbing, or friction, between the ball and the rug is what makes the ball stop rolling. External Force is required.
Answer:
t = 4.41 10⁻⁴ years
Explanation:
For this exercise we must use the concept of average life time, which is the time in which the quantity and substance decays in half
= ln2 / λ
Let's calculate the decay constant of plutonium
λ = ln2 /
λ = ln 2 / 2.44 10⁵
λ = 2.84 10⁻⁶ s⁻¹
Radioactive decay is a first order process
N = No e (-λ t)
Where N is the number of nuclei, the mass is this by molecular weight
m = N PM
m / PM = m₀ / PM e (- λ t)
m / m₀ = e (- λ t)
-λ t = ln (m / m₀)
t = -1 /λ ln (m/m₀)
t = - 1 / 2.84 10⁻⁶ ln (0.1 / 0.35)
t = 4.41 10⁻⁴ years
Answer:
as the period decreases, the frequency and energy of the wave increase
Explanation:
Electromagnetic waves are oscillations of the electric and magnetic fields, described by maxwell's equations, the speed of the wave is called the speed of light
c = λ f
E = E cos (kx - wt)
Angular velocity is related to frequency and period.
w = 2π f = 2π / T
Let's analyze what happens when the wave period decreases, angular velocity and frequency increase.
This increase in frequency is reflected with the Planck equation in wave energy
E = h f
Therefore the wave carries more energy and can lead to stronger interactions with matter.
In summary, as the period decreases, the frequency and energy of the wave increase