Lead is often used to block out radiation
(a) 9.8 m/s/s
This never changes.
Answer: 28.1 amu
Explanation:
Mass of isotope 1 = 27.98 amu
% abundance of isotope 1 = 92.21% = 
Mass of isotope 2 = 28.98 amu
% abundance of isotope 2 = 4.70% = 
Mass of isotope 3 = 29.97 amu
% abundance of isotope 2 = 3.09% = 
Formula used for average atomic mass of an element :

![A=\sum[(27.98 )\times 0.922+(28.98)\times 0.047+(29.97)\times 0.0309]](https://tex.z-dn.net/?f=A%3D%5Csum%5B%2827.98%20%29%5Ctimes%200.922%2B%2828.98%29%5Ctimes%200.047%2B%2829.97%29%5Ctimes%200.0309%5D)

Therefore, the average atomic mass of silicon is 28.1 amu
Answer:
<h3>The answer is 150 kPa</h3>
Explanation:
The new pressure can be found by using the formula for Boyle's law which is

Since we are finding the new pressure

From the question we have

We have the final answer as
<h3>150 kPa</h3>
Hope this helps you