Answer:

Explanation:
Here we want to find the largest area of a circle that can be made from a piece of thread 25.2 cm long, assume no knot
.
This means that the circumference of the circle must equal to the length of the thread, so we can write:
L = 25.2 cm
And the circumference can be written as:

where
r is the radius of the circle
Solving for r, we find the radius:

The area of a circle is given by the formula

So in this case, we find:

Composed of molecules formed by atoms of two or more different elements.
Answer : The molality of sodium chloride is, 1.79 m
Explanation :
To calculate the molality of solution, we use the equation:

Where,
= Given mass of solute (sodium chloride) = 49 g
= Molar mass of solute (sodium chloride) = 58.5 g/mol
= Mass of solvent (water) = 469 g
Now put all the given values in above equation, we get:

Hence, the molality of sodium chloride is, 1.79 m
Electrical energy can be converted to mechanical energy, light energy, heat energy, etc. Chemical energy can be converted to electrical energy. Thermal energy can be converted to heat energy.