Answer:
In our modern periodic table, the horizontal rows are known as periods , and the elements belonging to same period have same numbers of shells .
for example :
lithium, beryllium , boron , carbon , nitrogen , oxygen, fluorine and neon are in same period and have total 2 shells .
It requires more energy to boil an substance than to melt it (with special exceptions). When something is boiled you are furthering the distance between the already stretched out molecules which will require more energy to do so, also in most cases you will be creating a vapor from boiling which has a high kinetic energy value.
<span>Both of the containers have exactly the same pressure.</span>
Answer:
D. Streak.
Explanation:
A mineral, in simple terms, can be defined as a solid inorganic substance that occurs in a pure form with a specific crystal structure. A mineral is identified based on its physical properties which include luster, color, streak, crystal shape, etc.
The color of the powdered form of a mineral is called a streak. A streak is a useful property in distinguishing sulfide and oxide minerals. To check the color of a mineral, it is rubbed against the surface of a ceramic streak plate or a piece of unglazed ceramic. In its finely powdered form, a mineral is easy to identify.
Therefore, option D is correct.
The answer is 10 because if their is 20 molecules of hydrogen then their is one oxygen molecule for each which results in 20 divided by two which equals 10
