18. <em>Penny</em>: Used to measure mineral toughness; <em>Cuprum</em> penny's toughness is 3.
<em>Hand Lens</em>: Could be used to measure the hardness of the mineral; the glass can be used as a scratch platform; it can also be used to test the luster of the mineral tile; the mineral is rubbed in the glass portion of the tile and a powdery strike of the stone is given to distinguish the colour of the rock.
<em>Geological hammer</em>: Used to break down the mineral to assess whether or not it has cleavage, and to detect fractures
<em>Pocketknife</em>: Used to define mineral tenacity; the tenacity of the mineral can be silky, malleable, sectile, elastic, or flexible.
17. Volcanoes are holes or cracks in the lava-flowing crust of the earth. They are normally placed on the borders of tectonic plates as they are created as the plates clash and create gaps. In other words, volcanoes located at convergent-plate boundaries.
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Answer:
The activity factor was modified. Ambulating indicates that the person is active. Even small activities require energy. So, people who can walk around and aren’t bedridden expend more calories than people who need to be on bedrest all day. Also, when the stress factor was changed to severe infection, the caloric requirement increased. This increase is probably because the immune system requires more energy to fight off the infection
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Answer:
is required to do something
Answer:<u><em>When water freezes, it contracts, decreasing the water level in a lake. Water in a lake freezes from the bottom up, killing most aquatic organisms. When water in a lake freezes, it floats, providing insulation for organisms below.</em></u>
Explanation:
C)temperature and rainfall
Explanation:
Temperature and rainfall are the most important physical factors that shapes the characteristics of an ecosystem.
Temperature is the degree of hotness or coldness of a place. It is mostly as a result of the solar radiation it receives.
Rainfall is a form of precipitation in which water falls under gravity in liquid form.
They are both by far the most important factors that shapes ecosystems.
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