Because the atoms are separating bc of the heat. A solid has really compact atoms so if it was melted its atoms would become looser and form a liquid
If you are asking about the average atomic mass, the number under the element, then it is "the sum of the masses of it's isotopes." You should know what isotopes are, (if not, it's when an element can have more or less neutrons than other atoms of the same element) so what it means is that the number is the average amount naturally found in nature ( or naturally produced). For example, carbon's number is 12.0107. Since the average atomic mass number is so close to 12, it must mean that carbon's most abundant iostope is Carbon-12. The decimals mean there are Carbon-13s in nature, but not as abundant as Carbon-12. In some cases, there can be as many Carbon-11s(which isn't stable, but this is an example) as Carbon-13s, so the number is on 12, so you have to pay attention to which isotopes are listed as natural.
Combustion of <span>acetylene :
</span><span>molar ma</span>ss acetylene ( C₂H₂ ) = 26.0 g/mol and CO₂ = 44.0 g/mol
<span>
2 C₂H₂ + 5 O₂ ---> 4 CO₂ + 2 H₂O
</span>
2 moles C₂H₂ --------> 4 moles CO₂
? moles C₂H₂ --------> 1.10 moles CO₂
moles C₂H₂ = 1.10 * 2 / 4
moles C₂H₂ = 0.55 moles of C₂H₂
Mass acetylene:
m = n * mm
m = 0.55 * 26.0
m = 14.3 g
hope this helps!
Answer. Chemical reaction had occurred and both the powders are different substances.
Explanation:
As density is an intensive property of the substance.Which means that different substance have different densities.
Density = 
Density of powder 1, 
Density of powder 2, 
On comparing both the densities of the powders we can say that both the substances are different. So we can conclude that the chemical reaction had occurred.
Answer:
Solid to liquid
Explanation:
Entropy is a state of randomness or disorderliness of the particles of a system. Some part of the heat energy of a system is related to the state of disorder or randomness of the particles of the system.
The entropic level of a system depends on two of major factors:
1. Temperature: Entropy increases with temperature rise due to the fact that the randomness of the particles of a system increases at a higher temperature.
2. Physical state of matter: The increasing order of entropy is:
Solid < Liquid < Gas
Gases are the most disordered and have the highest entropy. In moving from solid to liquid to gas, entropy of a system would increase.