200 calories.
Explanation:
The (latent) heat of fusion of a material, is either one of:
1) the heat required to melt the material without
temperature change or
2) the heat removed from the material to freeze it
without temperature change.
For water this latent heat is 80 cal/g. Multiply this by
2.5 g to get 200 cal.
Answer:
<em>the <u>valency of an element</u> is its combining capacity that is the number of electrons it requires to lose, gain or share in order to become neutral.</em>
[ An element can become neutral if it completes it's octet. That is if an element has 8 electrons in it'd outermost shell then it is considered neutral ]
- The valence of Magnesium is 2 because it requires to lose 2 electrons to become neutral.
- whereas, the valence of Oxygen is 2 because it needs to gain 2 electrons to become stable.
Hence they both have the same valence.
One may say that oxygen's valence is -2 while that of Magnesium is + 2. It's meaning is still the same but "-" sign indicates that oxygen will be gaining electrons in the process of becoming stable.
Answer:
The volume will decrease and the balloons will be smaller
In order to compounds to be serparated, chemical means are needed. For example, if it you want to separate hydrogen and oxygen in the water ,an electric current should flow through it and that is a kind of chemical means(it is related to the chemical properties of the elements .)
While ,if there is a mixture ,it's components are rather separated easily in physical means. For instance, if you have a salt water, you are able to divide them by using each physical properties. Water is able to turn to a state of gas by evaporating or boiling. Using such properties, you could separate water from salt. Therefore, separating compounds and mixtures are all about the components physical or chemical properties.
So, the answer is a. I hope it will help you^^
Solutes are when a substance is dissolved into another substance, so if it's dissolved, it is combined completely, and you can't see it anymore :)
