2 Al+ 3 CuO-> 1 Al2O3+ 3Cu
An element is a pure substance that cannot be separated or divided into simpler substances by any method (physical or chemical). The four common elements in all the living organisms are carbon, oxygen, hydrogen, nitrogen.
Thus, the four elements that make up about 96 % of body matter are carbon, oxygen, hydrogen, nitrogen (c).
It would be B, so yeah hope that helps ya ;)
Answer:
Na₂CO₃•H₂O
Explanation:
After it is heated, the remaining mass is the mass of sodium carbonate.
30.2 g Na₂CO₃
Mass is conserved, so the difference is the mass of the water:
35.4 g − 30.2 g = 5.2 g H₂O
Convert masses to moles:
30.2 g Na₂CO₃ × (1 mol Na₂CO₃ / 106 g Na₂CO₃) = 0.285 mol Na₂CO₃
5.2 g H₂O × (1 mol H₂O / 18.0 g H₂O) = 0.289 mol H₂O
Normalize by dividing by the smallest:
0.285 / 0.285 = 1.00 mol Na₂CO₃
0.289 / 0.285 = 1.01 mol H₂O
The ratio is approximately 1:1. So the formula of the hydrate is Na₂CO₃•H₂O.
Bob adds heat to a liquid substance. When enough heat is added, the liquid would undergo a phase transition from the liquid to the vapor phase. This process is called evaporation. It is an endothermic process where heat should be supplied to the system for the process to happen. The temperature of the system, when enough heat is supplied to allow phase transition, is called the boiling point. It is the temperature when the substance starts to boil in turn to a gas or a vapor. The heat that is associated during boiling is called the latent heat of vaporization. It is the heat that is absorbed during the phase change without changing the temperature of the system.
