The answer is quartz where the hardness is 7.
Can scratch glass easily. This is where most granites are rated in terms of hardness
Answer:
A) Hydrogen atoms fuse into larger helium atoms and release energy in the form of solar radiation.
Explanation:
dont know why that person said c..
Answer:Metals are an excellent conductor of electricity and heat because the atoms in the metals form a matrix through which outer electrons can move freely. Instead of orbiting their respective atoms, they form a sea of electrons that surround the positive nuclei of the interacting metal ions.
Explanation:
Hi There! :)
<span>Which elements in the periodic table are metalloids or have semimetallic properties?
</span><span>Boron, Silicon, Germanium, Arsenic, Antimony, and Polonium are all metalloids. Some people consider Astatine a metalloid</span>
Answer:
<u> </u><u>85.952 ml</u> 
needed to titrate the excess complexing reagent .
Explanation:
Lets calculate
After addition of 80 ml of EDTA the solution becomes = 20 + 70 = 90 ml
As the number of moles of 
=
=
=0.01172
Molarity = 
=
=0.000586 moles
Excess of EDTA = concentration of EDTA - concentration of CoSO4
= 0.009005 - 0.000586
= 0.008419 M
As M1V1 ( Excess of EDTA ) = M2V2 
V2 =85.952 ml
Therefore , <u>85.952 ml </u> needed to titrate the excess complexing reagent .
