Answer:
a)
, b) 
Explanation:
a) The Hooke's law states that spring force is directly proportional to change in length. That is to say:

In this case, the force is equal to the weight of the object:



The spring constant is:



b) The length of the spring is:




We simply asked to name three uses for mercury.
The most common and well-known use of mercury is the production of thermometers. It's property to stay liquid at room temperature makes it ideal for a temperature indicator. However, the use of mercury is thermometers has been phased out due to health hazards.
It is also used to form an amalgam which is the result of its combination with silver or gold. Mercury has been used to mine gold and silver. This application has also been phased out.
Today's use of mercury includes mercury-vapor lamps which are the bright lamps used in high-ways.
Answer: C. Metals are found on the left side of the periodic table.
Explanation:
The periodic table contains vertical columns called as groups and horizontal rows called as periods.
Period 2 contains 8 elements which are lithium, beryllium , boron , carbon, nitrogen, oxygen , fluorine and neon. Only Lithium and beryllium are metals.
Group 18 contains all the noble gases which are all non metals.
Metals are the elements which loose electrons easily and form positive ions. Non-metals are the elements which can gain electrons easily and form negative ions.
Metals are present on left side of the periodic table and as we move to right side of the periodic table , the metallic character decreases and thus non metals are found on the right side of the periodic table.
There is approximately 2.54 cm that equals to 1 inch. So your closet answer would be the first choice. :)