Answer:
Thus the time taken is calculated as 387.69 years
Solution:
As per the question:
Half life of
= 28.5 yrs
Now,
To calculate the time, t in which the 99.99% of the release in the reactor:
By using the formula:

where
N = No. of nuclei left after time t
= No. of nuclei initially started with

(Since, 100% - 99.99% = 0.01%)
Thus

Taking log on both the sides:


t = 387.69 yrs
It does not violate the law of conservation of energy. The oscillation stops when the energy is lost and the energy is lost because it becomes heat that is created by the air resistance and many other forces found in the surrounding of the oscillating spring.
Answer:
Mg and HCl
Explanation:
Here, we want to get the combination that could be used in the production of the needed hydrogen
An important chemical property of inorganic acids is that when they react with metals, they give off hydrogen gas in conjunction with the formation of a salt
HCl is a mineral acid while Mg is a metallic substance
So the reaction between this metal and the mineral acids will give the needed hydrogen gas to be produced
The outer planets<span> are further away, larger and made up mostly of gas. The </span>inner planets<span> (in order of distance from the sun, closest to furthest) are Mercury, Venus, Earth and Mars. After an asteroid belt comes the </span>outer planets<span>, Jupiter, Saturn, Uranus and Neptune.</span>
The igneous rocks which were deposited on the surface and then cooled are known as extrusive. These rocks are a result of a magma reaching the surface of the Earth which cools the magma quickly. Examples are rhyolite, basalt, obsidian and andesite.