Answer:
1. In general, the best shields will be able to block a spectrum of radiation. Aboard the space station, the use of hydrogen-rich shielding such as polyethylene in the most frequently occupied locations, such as the sleeping quarters and the galley, has reduced the crew's exposure to space radiation.
2. It absorbs harmful ultraviolet radiation from the sun, helps keep Earth's surface warm via the greenhouse effect, and reduces temperature extremes between day and night. ... So, thanks to gravity, although some of Earth's atmosphere is escaping to space, most is staying here.
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Hey there,
Question: "<span>What is the half life of Strontium-90? Explain your answer"
Answer: </span>28.8 years / <span>Strontium-90 has 52 neutrons and 38 protons. </span>
Answer:
Option (2)
Explanation:
From the figure attached,
Horizontal component, 
![A_x=12[\text{Sin}(37)]](https://tex.z-dn.net/?f=A_x%3D12%5B%5Ctext%7BSin%7D%2837%29%5D)
= 7.22 m
Vertical component, ![A_y=A[\text{Cos}(37)]](https://tex.z-dn.net/?f=A_y%3DA%5B%5Ctext%7BCos%7D%2837%29%5D)
= 9.58 m
Similarly, Horizontal component of vector C,
= C[Cos(60)]
= 6[Cos(60)]
= 
= 3 m
![C_y=6[\text{Sin}(60)]](https://tex.z-dn.net/?f=C_y%3D6%5B%5Ctext%7BSin%7D%2860%29%5D)
= 5.20 m
Resultant Horizontal component of the vectors A + C,
m
= 4.38 m
Now magnitude of the resultant will be,
From ΔOBC,

= 
= 
= 6.1 m
Direction of the resultant will be towards vector A.
tan(∠COB) = 
= 
= 
m∠COB = 
= 46°
Therefore, magnitude of the resultant vector will be 6.1 m and direction will be 46°.
Option (2) will be the answer.
Benthos
Option b is the answer
Answer: Option (D) is the correct answer.
Explanation:
The given elements Li, C and F are all second period elements. So, when we move from left to right across a period then there occurs increase in number of valence electrons as there occurs increase in total number of electrons.
So, it means more electrons are added to the same energy level.
Thus, we can conclude that a property of valence electrons for each element is located in the same energy level is common in the given elements.