Mass, if you know what element you are working with.
Answer:- 0.88
Solution:- Masses of silver and copper metals are given and we are asked to calculate the percentage of silver in the alloy.
mass percent of Ag = 
Mass of Ag = 17.6 g
mass of Cu = 2.40 g
mass of alloy = 17.6 g + 2.40 g = 20.0 g
Let's plug in the values in the formula:
mass percentage of Ag = 
mass percentage of Ag = 88%
So, the mass percentage of silver in sterling silver is 88% and in decimal form it is 0.88.
Answer : Chemical energy to thermal energy
Explanation : When the welding torch uses the acetylene fuel for producing flame it is using the chemical acetylene to generate energy in form of light, after the flame is produced the fuel is used for melting a metal which is utilizing the thermal energy. So the ultimate final product is generated from chemical to thermal and so the energy transformation is from chemical energy to thermal energy.
Answer:
A. Sublimation of camphor
The number of neon moles that occupy a volume of 14.3 l at STP is calculated as follows
At STP 1 mole = 22.4 liters
what about 14.3 liters
by cross multiplication
= (1 mole x 14.3 l)/22.4 l =0.638 moles of neon