Physical Properties<span>: </span>Physical properties<span> can be observed or measured without changing the composition of matter. </span>Physical properties<span> are used to observe and describe matter. so physical changes are the change in temperature of the land and the evaporation of water and change humidity of the air. chemical change is the ripening of the orange</span>
<u>Epipelagic </u>zones are warm, well lit, and have lots of marine life.
Explanation:
This is the topmost zone of the oceans extending about 200 meters from the ocean surface. This zone is well lit because sunlight is able to penetrate this layer before it discusses as it penetrates deeper into the ocean. Therefore, this epipelagic zone is able to sustain plankton (that are photosynthetic). Plankton form the base of marine life which is why they support a large marine ecosystem in the epipelagic zone and thie energy flow even to the deeper abyssopelagic zone.
Answer: high pressure because it's stable
Explanation:
Air mass is volume of air which has stable temperature, humidity and pressure horizontally. Over time, each air mass acquires properties of the region by residing over same part of a surface.
Areas of low pressure and high pressure occur where there is warm air and cold air respectively. An air mass usually forms over an area of high pressure. Warm air rises up and cold air takes its place. Warm air has low density and low pressure where as cold air has high density and pressure and therefore, sinks to the bottom. This is a stable condition. The movement of air mass is responsible for maintenance of temperature conditions on Earth.
A fluorine element has 7 valence electrons.
A stable fluorine ion should have 8 valence electrons.
So fluorine gains an extra electron.
Thus, the most stable monatomic ion is 
Answer: There must be the same number of atoms of each element on both sides of the equation.
Explanation: This is the only way the equations will be balanced. Adding the coefficients to see if they are equal will not guarantee that the equations are balanced becuase coefficients can be turned into subscripts.
