Answer:
A
Explanation:
Hot air is less dense therefore it rises. Cold air is more closely packed therefore it is more dense. Less dense things rise while more dense things sink.
Answer: The bond between boron and hydrogen in boron trihydride is covalent bond.
Explanation:
The type of bonding between the atoms forming a compound is determined by using the electronegativity difference between the atoms. According to the pauling's electronegativity rule:
- If
, then the bond is non-polar. - If
, then the bond will be covalent. - If
, then the bond will be ionic.
We are given:
Electronegativity for boron = 2.0
Electronegativity for hydrogen = 2.1
As, 
is less than 1.7 and not equal to 0. Hence, the bond between boron and hydrogen is covalent bond.
Answer:A mixture is a mechanical combination of several elements or compounds. Mixtures are used in cooking, chemical manufacturing, and a lot of other processes. A good mixture with the materials evenly distributed facilitates a good after mixture process. That might be a chemical reaction or a great cake. One mixture that we see the results of a lot is the mixture of water, gravel, and Portland cement that, after a good mix, becomes concrete. Other mixtures might include the various plastics and epoxies that require two or more parts to become a finished product. There are so many possible mixtures out there I’d suggest chemical engineering books , chemistry books in general, cook books, books on construction processes, and many other possible sources of mixtures and the results of using them.
Explanation:
