<u>Answer:</u> The density of substance is 
<u>Explanation:</u>
To calculate density of a substance, we use the equation:

We are given:
Mass of substance = 61.6 g
Volume of substance = 
Putting values in above equation, we get:

Hence, the density of substance is 
<u>Answer:</u> The number of moles of strontium bicarbonate is 
<u>Explanation:</u>
Formula units are defined as lowest whole number ratio of ions in an ionic compound. It is calculate by multiplying the number of moles by Avogadro's number which is 
We are given:
Number of formula units of 
As,
number of formula units are contained in 1 mole of a substance.
So,
number of formula units will be contained in =
of strontium bicarbonate.
Hence, the number of moles of strontium bicarbonate is 
The sum of the masses of the reactants must equal the sum of the masses of the products; as required by
the Principle of Conservation of Mass.
Answer:
Note that melting and vaporization are endothermic processes in that they absorb or require energy, while freezing and condensation are exothermic process as they release energy.
Riley can either change the surface area of the object or can change the slipperiness of the material.