Answer:
(d) burning a log.
(b) toasting a slice of bread;
Explanation:
Chemical change -
A chemical change refers to , the change in which a new compound is formed .
From the question ,
Its is not a chemical process , since no new compound is formed , these is only change in state as the liquid is turning to gaseous sate .
It is not a chemical process , as no new substance is formed .
- toasting a slice of bread
It is a chemical change , in which bread surface is deposited by a brown coat via the process of heating , even this process is a irreversible in nature .
It is a chemical change , as with the help of heating , the wood is turning to ashes .
<span>47.88 g/mol is the awsner your welcome</span>
Sure. Whith what do you need help?
Answer:
Energy lost is 7.63×10⁻²⁰J
Explanation:
Hello,
I think what the question is requesting is to calculate the energy difference when an excited electron drops from N = 15 to N = 5
E = hc/λ(1/n₂² - 1/n₁²)
n₁ = 15
n₂ = 5
hc/λ = 2.18×10⁻¹⁸J (according to the data)
E = 2.18×10⁻¹⁸ (1/n₂² - 1/n₁²)
E = 2.18×10⁻¹⁸ (1/15² - 1/5²)
E = 2.18×10⁻¹⁸ ×(-0.035)
E = -7.63×10⁻²⁰J
The energy lost is 7.63×10⁻²⁰J
Note : energy is lost / given off when the excited electron jumps from a higher energy level to a lower energy level
Answer:
It makes the pasta to get hot faster and boil quicker.
Explanation:
Adding salt to water actually raises the boiling point of the water, due to a phenomenon called boiling point elevation. Essentially, adding any non-volatile solute such as salt to a liquid causes a decrease in the liquid’s vapour pressure. A liquid boils when the vapour pressure above it equals atmospheric pressure, so a lower vapour pressure means you need a higher temperature to boil the water. The reason salt makes water boil faster has to do with specific heat capacities, or the energy it takes to raise the temperature of a substance. Salt ions dissolved in water bind to water molecules, holding them stable and making it harder for them to move around. As a result, the non-salt bound water molecules receive more of the energy provided by the stove, and therefore they get hot faster and boil quicker.
