Answer: She is incorrect to conclude that the reaction is endothermic.
As in the second trial, the temperature has increased by 20 °C , that means the heat has been released and energy is released in exothermic reactions.
Exothermic reactions: The reactions in which the energy of the products is less than the energy of the reactants, and the excess energy is released as heat.
Endothermic reactions: The reactions in which the energy of the products is more than the energy of the reactants, and the excess energy is absorbed as heat.
Answer:
The only difference between a planet and a dwarf planet is the area surrounding each celestial body. A dwarf planet has not cleared the area around its orbit, while a planet has.
Explanation:
the three criteria of the IAU for a full-sized planet are: It is in orbit around the Sun. It has sufficient mass to assume hydrostatic equilibrium (a nearly round shape). It has "cleared the neighborhood" around its orbit .
Answer:
Just as distance and displacement have distinctly different meanings (despite their similarities), so do speed and velocity. Speed is a scalar quantity that refers to "how fast an object is moving." Speed can be thought of as the rate at which an object covers distance. A fast-moving object has a high speed and covers a relatively large distance in a short amount of time. Contrast this to a slow-moving object that has a low speed; it covers a relatively small amount of distance in the same amount of time. An object with no movement at all has a zero speed.
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
