Answer:
321.6 g/Mol
Explanation:
mass of solvent in kilograms = 90g/1000 = 0.09 Kg
Given that;
ΔTf = Kf . m . i
Where;
Kf = freezing point constant = 4.25 °C/Kg mol
m = molality of the solution
i = Van't Hoff factor = 1 (since the substance is molecular)
ΔTf = freezing point of pure solvent - freezing point of solution
freezing point of pure solvent = 3 °C
ΔTf = 3 °C - 2.1 °C
ΔTf = 0.9 °C
0.9= 4.25 * 6.13/M/0.09 * 1
0.9= 26.0525/M * 1/0.09
0.9 = 26.0525/0.09 M
0.9 * 0.09M = 26.0525
M = 26.0525/0.9 * 0.09
M= 321.6 g/Mol
Physical is texture. chemical is ability to react with other elements. chemical is ability to conduct heat. hardness is physical. lack of ability to rust is chemical. state is physical.
<span>4000 kilogram/cubic meter
http://www.calculator.net/density-calculator.html?cdensity=&cdensityunit=kilogram%2Fcubic+meter&cvol...
</span>
Answer:
Stone A
Explanation:
Measuring density is an easiest way to determine if two similar looking substances are same or not. Here also we need to perform the density test for each stone that is suspected to be fake diamond. We will calculate the density of each stone and compare it with the density of original diamond.
Density is calculated using the formula
It has been given in the question that both the substances have same volume of 0.15 
.
Density of stone A = 
= 3.47 
or after rounding off we get 3.5
Density of stone B = 
= 2.8
It is clear from the above calculation that the stone A has same density as the diamond but stone B lacks behind in density.
So, stone A could be the real diamond.
Answer:1. 5
Explanation: the element is boron and the atomic number is 5
