Make the following conversion. 0.075 m = _____ cm 7.5 75 0.0075 0.00075

Answer: Option (b) is the correct answer.

Explanation:

An open system is defined as the one where there will occur exchanges of matter as well as heat energy between the system and surrounding.

For example, when a boil water then its heat energy will move into the surrounding and also matter is moving to the surrounding in the form of water vapor or steam.

On the other hand, a system in which there will occur no exchange of matter but exchange of heat will occur from the system to the surrounding is known as a closed system.

For example, coffee placed in a cup covered with lid is a closed system.

Thus, we can conclude that the statement heat and matter are both able to enter or leave the system best expresses the definition of an open system.

Answer:

D.  27 13 Al

Explanation:

13 protons means atomic number 13.  The periodic table says element 13 is aluminum (Al).  27 is the atomic mass, made up of 13 protons (1 each) and 14 neutrons (also 1 each) for a total of 27 atomic mass.

Answer: Option (a) is the correct answer.

Explanation:

Conservation efforts means to carefully preserve or protect something. These efforts are fruitful when a majority of people or communities come together in order to preserve something good for the betterment of environment.

As when maximum number of people come lend their hands for help only then conservation efforts can be achieved.

For example, a city with maximum pollution can only be conserved when maximum groups of people decide to conserve plants or plant more number of trees.  

Thus, we can conclude that conservation efforts are most effective when conservation efforts are most effective when multiple groups cooperate.